| Word | Plural | Plural2 |
|---|---|---|
| house | houses | housen |
| money | moneys | monies |
| area | areas | areæ |
| problem | problems | problemata |
| person | persons | people |
| child | children | childer |
| staff | staffs | staves staff |
| idea | ideas | ideæ |
| basis | bases | baseis |
| fish | fish | fishes |
| daughter | daughters | daughtren |
| eye | eyes | eyen |
| status | statuses | statūs |
| brother | brothers | brethren |
| stone | stones | stone |
| gas | gases | gasses |
| museum | museums | musea |
| henry | henries | henrys |
| tree | trees | treen |
| fig. | fig. | figs. |
| pair | pairs | pair |
| curriculum | curricula | curriculums |
| bus | buses | busses |
| index | indexes | indices |
| roof | roofs | rooves |
| focus | foci | focuses |
| self | selves | selfs |
| drama | dramas | dramata |
| no. | nos. | no.'s |
| percent | percent | percents |
| formula | formulae | formulas formulæ |
| laura | lauras | laurae |
| medium | media | mediums |
| fox | foxes | foxen |
| complex | complexes | complices |
| album | albums | alba |
| ticket | tickets | tix |
| folk | folk | folks |
| louis | louis | louises |
| minimum | minima | minimums |
| villa | villas | villae |
| craft | craft | crafts |
| knee | knees | kneen |
| cloth | cloths | clothes |
| piano | pianos | piani |
| penny | pennies | pence |
| forum | forums | fora |
| taxi | taxis | taxies |
| appendix | appendices | appendixes |
| equilibrium | equilibriums | equilibria |
| lamb | lambs | lamber lambren |
| spectrum | spectra | spectrums |
| maximum | maxima | maximums |
| virus | viruses | viri virii |
| beef | beef | beefs beeves |
| tobacco | tobaccos | tobaccoes |
| matrix | matrices | matrixes |
| referendum | referenda | referendums |
| bureau | bureaus | bureaux |
| bonus | bonuses | boni |
| handful | handfuls | handsful |
| bias | biases | biasses |
| cow | cows | cattle kine |
| serum | serums | sera |
| surplus | surpluses | surplusses |
| premium | premiums | premia |
| canterbury | canterburys | canterburies |
| lion | lion | |
| echo | echoes | echos |
| apparatus | apparatuses | apparatus |
| canvas | canvasses | canvases |
| shoe | shoes | shoon |
| dilemma | dilemmas | dilemmata |
| specimen | specimens | specimina |
| genius | geniuses | genii |
| mucosa | mucosae | mucosas |
| sandwich | sandwiches | sandwichs |
| arena | arenas | arenae arenæ |
| swan | swans | swan |
| madame | madames | mesdames |
| plasma | plasmas | plasmata |
| stadium | stadiums | stadia |
| momentum | momentums | momenta |
| flora | floras | florae floræ |
| offspring | offspring | offsprings |
| asylum | asylums | asyla |
| vacuum | vacuums | vacua |
| deer | deer | deers |
| memorandum | memorandums | memoranda |
| consortium | consortia | consortiums |
| li | lis | li |
| lotus | lotuses | loti |
| aquarium | aquaria | aquariums |
| cargo | cargos | cargoes |
| iris | irises | iris irides |
| plus | pluses | plusses |
| telly | tellys | tellies |
| zero | zeroes | zeros |
| colon | colons | cola |
| manifesto | manifestos | manifestoes manifesti |
| molecule | molecules | moleculæ |
| diploma | diplomas | diplomata |
| lb | lbs | lbs. |
| corpus | corpora | corpuses |
| thou | thine | |
| trout | trout | trouts |
| trolley | trollies | trolleys |
| hepatitis | hepatitises | hepatitides |
| nucleus | nuclei | nucleuses |
| radius | radii | radiuses |
| asthma | asthmas | asthmata |
| skeleton | skeletons | skeleta |
| petroleum | petroleums | petrolea |
| cannon | cannon | cannons |
| handkerchief | handkerchiefs | handkerchieves |
| peninsula | peninsulas | peninsulae |
| cohen | cohens | cohanim |
| military | military | militaries |
| syllabus | syllabi | syllabuses |
| costa | costas | costae |
| mungo | mungos | mungoes |
| yuan | yuan | yuans |
| dwarf | dwarfs | dwarves |
| turf | turfs | turves turf |
| phoenix | phoenix | phoenixes phoenices |
| lexicon | lexica | lexicons |
| trauma | traumas | traumata |
| penis | penises | penes |
| bee | bees | been |
| scarf | scarves | scarfs |
| plateau | plateaus | plateaux |
| embryo | embryos | embryones |
| oesophagus | oesophagi | oesophaguses |
| pizza | pizzas | pizze |
| moran | morans | moran ilmoran |
| sultan | salateen | |
| concerto | concertos | concerti |
| militia | militias | militiae |
| pneumonia | pneumonias | pneumoniæ |
| sperm | sperm | sperms |
| ethos | ethe | ethea ethoses |
| bream | bream | breams |
| continuum | continuums | continua |
| veto | vetoes | vetos |
| tallis | tallises | talleitim tallisim tallism |
| aura | aurae | auræ auras |
| commando | commandos | commandoes |
| embargo | embargoes | embargos |
| boar | boars | boar |
| volcano | volcanos | volcanoes |
| placebo | placebos | placeboes |
| carp | carp | carps |
| cortex | cortexes | cortices |
| mouthful | mouthfuls | mouthsful |
| fauna | faunae | faunas faunæ |
| palazzo | palazzos | palazzi |
| tuna | tuna | tunas |
| herring | herrings | herring |
| goldfish | goldfish | goldfishes |
| inertia | inertias | inertiae inertiæ |
| tempo | tempos | tempi |
| aroma | aromas | aromata |
| motto | mottos | mottoes |
| sec | sec | secs |
| wharf | wharves | wharfs |
| pancreatitis | pancreatitises | pancreatitides |
| carcinoma | carcinomas | carcinomata |
| apex | apices | apexes |
| buffalo | buffaloes | buffalos buffalo |
| epithelium | epitheliums | epithelia |
| runner-up | runners-up | runner-ups |
| hose | hoses | hosen |
| marquis | marquises | marquis |
| bordeaux | bordeaux | bordeauxes bordeauxs |
| piazza | piazzas | piazze |
| fungus | fungi | funguses |
| abdomen | abdomens | abdomina |
| retina | retinas | retinae retinæ |
| proviso | provisos | provisoes |
| terminus | termini | terminuses |
| nausea | nauseas | nauseae nauseæ |
| prospectus | prospectuses | prospectus |
| schema | schemata | schemas |
| chick | chicks | chicken |
| hysteria | hysterias | hysteriæ |
| vagina | vaginas | vaginae vaginæ |
| alkali | alkalies | alkalis |
| idiom | idioms | idiomata |
| stigma | stigmata | stigmas |
| pollock | pollocks | pollock |
| nova | novae | novas |
| mink | mink | minks |
| chub | chubs | chub |
| golding | goldings | goldinges |
| symposium | symposiums | symposia |
| bede | bedes | beden |
| atlas | atlases | atlantes |
| dogma | dogmas | dogmata |
| spokesperson | spokespersons | spokespeople |
| persona | personas | personae personæ |
| millennium | millennia | millenniums |
| lymphoma | lymphomata | lymphomas |
| siren | sirens | sirenes |
| fiasco | fiascos | fiascoes |
| minibus | minibuses | minibusses |
| facsimile | facsimiles | facsimilia |
| mosquito | mosquitos | mosquitoes |
| rendezvous | rendezvous | rendezvouses |
| saliva | salivas | salivae salivæ |
| catfish | catfish | catfishes |
| salesperson | salespersons | salespeople |
| charisma | charismas | charismata |
| enigma | enigmas | enigmata |
| shrimp | shrimp | shrimps |
| zebra | zebra | zebras |
| metropolis | metropolises | metropoleis |
| pendulum | pendulums | pendula |
| torso | torsos | torsi |
| chateau | chateaux | chateaus |
| panorama | panoramas | panoramata |
| ghetto | ghettos | ghettoes ghetti |
| casino | casinos | casinoes casini |
| chad | chad | chads |
| sock | socks | sox |
| foetus | foetuses | foeti |
| opium | opiums | opia |
| crux | cruxes | cruces |
| rpm | rpms | rpm's |
| mademoiselle | mademoiselles | mesdemoiselles |
| loco | locos | locoes |
| moratorium | moratoriums | moratoria |
| thesaurus | thesauri | thesauruses |
| sen | sens | sen |
| helix | helixes | helices |
| comma | commas | commata |
| hernia | hernias | herniae herniæ |
| grouse | grouse | grouses |
| airbus | airbusses | airbuses |
| tableau | tableaux | tableaus |
| auditorium | auditoriums | auditoria |
| soprano | sopranos | soprani sopranoes |
| chilli | chillis | chillies |
| pelvis | pelvises | pelves |
| davy | davys | davies |
| signor | signors | signori |
| partridge | partridges | partridge |
| prawn | prawn | prawns |
| magma | magmas | magmata |
| salmonella | salmonellas | salmonellae |
| lumen | lumens | lumina |
| phosphorus | phosphoruses | phosphori |
| pancreas | pancreases | pancreata |
| cello | cellos | celli |
| ultimatum | ultimatums | ultimata |
| angelica | angelicas | angelica |
| epitome | epitomes | epitomai |
| rectum | recta | rectums |
| perch | perches | perch |
| hydra | hydras | hydrae hydræ |
| walkman | walkmans | walkmen |
| plenum | plenums | plena |
| fresco | frescos | frescoes |
| octopus | octopuses | octopi octopodes octopii |
| basilica | basilicas | basilicae |
| gymnasium | gymnasia | gymnasiums |
| bronchitis | bronchitises | bronchitides |
| veg | vegs | veg |
| dictum | dicta | dictums |
| tornado | tornados | tornadoes |
| encyclopaedia | encyclopaedias | encyclopaediae |
| neuron | neurons | neura |
| lacuna | lacunae | lacunas |
| spacecraft | spacecraft | spacecrafts |
| pegasus | pegasuses | pegasi |
| halo | halos | haloes |
| negro | negroes | negros |
| darcy | darcys | darcies |
| melodrama | melodramas | melodramata |
| domino | dominos | dominoes |
| beaver | beavers | beaver |
| aria | arias | arie |
| milieu | milieux | milieus |
| presidium | presidia | presidiums |
| vortex | vortexes | vortices |
| catapult | catapults | catapultæ |
| regatta | regattas | regatte |
| wildfowl | wildfowls | wildfowl |
| mamma | mammae | mammas |
| squid | squids | squid |
| chairperson | chairpersons | chairpeople |
| pic | pics | pix |
| cowan | cowans | cowanis |
| half-brother | half-brothers | half-brethren |
| lamina | laminas | laminae |
| uterus | uteri | uteruses |
| aurora | auroras | aurorae |
| mackerel | mackerel | mackerels |
| portico | porticos | porticoes |
| reindeer | reindeers | reindeer |
| stratum | stratums | strata |
| quorum | quorums | quora |
| shellfish | shellfish | shellfishes |
| influenza | influenzas | influenze |
| archipelago | archipelagos | archipelagoes |
| anathema | anathemas | anathemata |
| aegis | aegises | aegides |
| rostrum | rostra | rostrums |
| curia | curias | curiae |
| encyclopedia | encyclopedias | encyclopediae encyclopediæ |
| fowl | fowl | fowls |
| anus | anuses | ani |
| whiskey | whiskeys | whiskies |
| ganglion | ganglions | ganglia |
| crematorium | crematoriums | crematoria |
| lynx | lynxes | lynx |
| nightlife | nightlives | nightlifes |
| extravaganza | extravaganzas | extravaganze |
| virtuoso | virtuosos | virtuosi |
| broccoli | broccolis | broccoli |
| haddock | haddock | haddocks |
| starr | starrs | starra |
| grapefruit | grapefruits | grapefruit |
| gal | gal | gals |
| omnibus | omnibuses | omnibusses omnibi |
| detritus | detritus | detrita |
| fetus | fetuses | feti |
| regimen | regimens | regimina |
| bursa | bursae | bursæ |
| tuxedo | tuxedos | tuxedoes |
| amir | amirs | umara |
| mausoleum | mausoleums | mausolea |
| crescendo | crescendos | crescendi crescendoes |
| larva | larvas | larvae larvæ |
| alma | almas | alma |
| cul-de-sac | cul-de-sacs | culs-de-sac |
| duodenum | duodena | duodenums |
| enema | enemas | enemata |
| sow | sows | swine |
| scala | scalas | scalae |
| solarium | solariums | solaria |
| omega | omegas | omegala |
| sheaf | sheaves | sheafs |
| pitman | pitmans | pitmen |
| calculus | calculi | calculuses |
| kelvin | kelvins | kelvin |
| rhubarb | rhubarb | rhubarbs |
| grotto | grottos | grottoes |
| nexus | nexuses | nexus |
| bravado | bravados | bravadoes |
| opus | opuses | opera |
| forceps | forceps | forcipes forcepses |
| torpedo | torpedoes | torpedos |
| majlis | majlises | majlis |
| podium | podiums | podia |
| hoof | hoofs | hooves |
| oedema | oedemas | oedemata |
| mango | mangoes | mangos |
| asparagus | asparagus | asparaguses |
| extremity | extremities | extremitys |
| ballerina | ballerinas | ballerine |
| sis | sises | sisses |
| ri | ris | li |
| hiatus | hiatus | hiatuses |
| spoonful | spoonfuls | spoonsful |
| hertz | hertz | hertzes |
| magnum | magnums | magna |
| adenocarcinoma | adenocarcinomas | adenocarcinomata |
| staccato | staccatos | staccati |
| lichen | lichens | lichen |
| amnesia | amnesias | amnesiæ |
| beau | beaux | beaus |
| eczema | eczemata | eczemas |
| cent | cents | cent |
| antrum | antrums | antra |
| memento | mementos | mementoes |
| phobia | phobias | phobiæ |
| atrium | atria | atriums |
| praxis | praxes | praxises |
| char | chars | char |
| epsilon | epsilons | epsila |
| grice | grice | grices |
| antelope | antelope | antelopes |
| vermin | vermin | vermins |
| vita | vitae | vitas |
| marlin | marlin | marlins |
| rhinoceros | rhinoceros | rhinoceroses rhinoceri rhinocerotes |
| panacea | panaceas | panaceæ |
| terra | terras | terrae |
| drosophila | drosophilas | drosophilae |
| nikkei | nikkeis | nikkei |
| delirium | deliriums | deliria |
| starfish | starfishes | starfish |
| moose | moose | mooses |
| stucco | stuccoes | stuccos |
| cervix | cervixes | cervices |
| pantheon | pantheons | panthea |
| avocado | avocados | avocadoes |
| libretto | librettos | libretti |
| incubus | incubi | incubuses |
| gondola | gondolas | gondole |
| caucus | caucuses | caucusses |
| duomo | duomos | duomi |
| cameo | cameos | cameoes |
| zander | zanders | zander |
| stylus | styli | styluses |
| signorina | signorinas | signorine |
| axiom | axioms | axiomata |
| melanoma | melanomas | melanomata |
| urethra | urethras | urethrae |
| swordfish | swordfish | swordfishes |
| elect | elects | elect |
| valour | valours | lbl |
| addendum | addenda | addendums |
| nymph | nymphs | nymphæ |
| flounder | flounders | flounder |
| gallows | gallows | gallowses |
| calico | calicos | calicoes |
| vertigo | vertigos | vertigoes |
| plaice | plaice | plaices |
| supernova | supernovas | supernovae |
| sphinx | sphinxes | sphinges |
| atari | atari | ataris ataries |
| simile | similes | similia |
| larynx | larynges | larynxes |
| acropolis | acropolises | acropoleis |
| salvo | salvos | salvoes |
| femur | femurs | femora |
| disequilibrium | disequilibria | disequilibriums |
| clematis | clematises | clematis |
| latex | latices | latexes |
| corgi | corgis | corgwn |
| gazelle | gazelles | gazelle |
| placenta | placentae | placentas |
| nimbus | nimbi | nimbuses |
| libra | librae | libras |
| ditto | dittos | dittoes |
| clitoris | clitorises | clitorides |
| jellyfish | jellyfish | jellyfishes |
| compendium | compendiums | compendia |
| snipe | snipes | snipe |
| innuendo | innuendoes | innuendos innuendis |
| woodcock | woodcock | woodcocks |
| flamingo | flamingos | flamingoes |
| cactus | cacti | cactuses cactus |
| lexis | lexises | lexeis |
| epidermis | epidermides | epidermises |
| fracas | fracases | fracas |
| patina | patinas | patinae |
| herbarium | herbariums | herbaria |
| nene | nenes | nene |
| pandemonium | pandemoniums | pandemonia |
| springbok | springbok | springboks |
| conundrum | conundrums | conundra |
| chrysalis | chrysalises | chrysalides |
| emir | umara | |
| sarcophagus | sarcophagi | sarcophaguses |
| bimbo | bimbos | bimboes |
| antenna | antennae | antennas |
| imperium | imperia | imperiums |
| impresario | impresarios | impresari |
| hovercraft | hovercrafts | hovercraft |
| giraffe | giraffes | giraffe |
| pimlico | pimlicos | pimlicoes |
| condor | condors | condor |
| gnome | gnomai | gnomes |
| albatross | albatross | albatrosses |
| bitumen | bitumina | bitumens |
| corona | coronas | coronae coronæ |
| manservant | manservants | menservants |
| urethritis | urethritides | urethrites |
| quail | quail | quails |
| ermine | ermines | ermine |
| trachea | tracheas | tracheae tracheæ |
| uva | uvae | uvæ |
| bolus | boli | boluses |
| fascia | fascias | fasciae |
| fistful | fistfuls | fistsful |
| campanile | campaniles | campanili |
| thorax | thoraces | thoraxes |
| teaspoonful | teaspoonfuls | teaspoonsful |
| horsepower | horsepowers | horsepower |
| tsunami | tsunami | tsunamis |
| enteritis | enteritides | enteritises |
| genie | genii | genies |
| walrus | walruses | walrus walrusses walri walrii |
| emporium | emporiums | emporia |
| tench | tench | tenches |
| appendicitis | appendicitises | appendicitides |
| scherzo | scherzos | scherzi |
| autobahn | autobahns | autobahnen |
| armful | armfuls | armsful |
| adenoma | adenomas | adenomata |
| venturi | venturis | venturi |
| gauss | gausses | gauss |
| samurai | samurai | samurais |
| cupola | cupolas | cupolae |
| sanatorium | sanatoriums | sanatoria |
| portmanteau | portmanteaus | portmanteaux |
| anaphor | anaphors | anaphora |
| antiserum | antiserums | antisera |
| datum | data | datums |
| medusa | medusas | medusae medusæ |
| narcissus | narcissuses | narcissi |
| caribou | caribous | caribou |
| papyrus | papyri | papyruses |
| ceilidh | ceilidhs | ceilidhean |
| coney | coneys | conies |
| indigo | indigos | indigoes |
| wadi | wadis | wadies |
| ninja | ninja | ninjas |
| gringo | gringos | gringoes |
| nebula | nebulae | nebulas |
| gross | gross | grosses |
| fulcrum | fulcrums | fulcra |
| cardia | cardias | cardiae |
| crocus | crocuses | croci |
| fatwa | fatwas | fatawa |
| pinto | pintos | pintoes |
| bonsai | bonsai | bonsais |
| otaku | otakus | otaku |
| trilby | trilbys | trilbies |
| diva | dive | divas |
| abacus | abaci | abacuses |
| boa | boas | boae |
| pres. | pres | pres's |
| dermatitis | dermatitises | dermatitides dermatites |
| lev | leva | levs |
| waterfowl | waterfowl | waterfowls |
| triforium | triforia | triforiums |
| tango | tangos | tangoes |
| dodo | dodoes | dodos |
| narthex | narthexes | narthices |
| colossus | colossuses | colossi |
| huntsman | huntsmen | huntsmans |
| arboretum | arboretums | arboreta |
| cross-country | cross-countries | cross-countrys |
| angelfish | angelfish | angelfishes |
| bison | bison | bisons |
| mambo | mambos | mamboes |
| phylum | phyla | phylums |
| phage | phages | phage |
| dado | dados | dadoes |
| aqua | aquas | aquae |
| ply | plys | plies |
| dido | didos | didoes |
| trolleybus | trolleybuses | trolleybusses |
| gazebo | gazebos | gazeboes |
| vulva | vulvas | vulvae vulvæ |
| bilbo | bilbos | bilboes |
| stoma | stomata | stomas |
| automaton | automatons | automata |
| halfpenny | halfpennies | halfpence |
| cherub | cherubs | cherubim cherubims |
| kimono | kimonos | kimono |
| louse | lice | louses |
| zloty | zloty | zlotys zlote zlotych zloties |
| gestalt | gestalts | gestalten |
| contralto | contraltos | contralti |
| torus | tori | toruses |
| heathen | heathen | heathens |
| interregnum | interregnums | interregna |
| cisco | ciscos | ciscoes |
| toga | togas | togae togæ |
| brill | brills | brill |
| mater | maters | matres |
| agora | agorae | agoras |
| vila | vilas | vile |
| emphysema | emphysemas | emphysemata |
| eucalyptus | eucalypti | eucalyptuses |
| mozzarella | mozzarellas | mozzarelle |
| acacia | acacias | acaciae |
| stiletto | stilettos | stilettoes stiletti |
| cento | centos | centones |
| sumo | sumo | sumos |
| mimosa | mimosas | mimosae |
| clownfish | clownfish | clownfishes |
| banjo | banjos | banjoes |
| smiley | smileys | smilies |
| phallus | phalli | phalluses |
| polis | poleis | polises |
| lingo | lingos | lingoes |
| parabola | parabolas | parabolae parabolæ |
| ha'penny | ha'pennies | ha'pence |
| calypso | calypsos | calypsoes |
| cointreau | cointreaus | cointreaux |
| scrotum | scrotums | scrota |
| eisteddfod | eisteddfods | eisteddfodau |
| tupperware | tupperwares | tupperware |
| pallium | pallia | palliums |
| aorta | aortas | aortae |
| reticulum | reticula | reticulums |
| bravo | bravos | bravoes |
| athenaeum | athenaeums | athenaea |
| phylloxera | phylloxeras | phylloxerae |
| gi | gis | gi |
| lemma | lemmas | lemmata |
| lindy | lindys | lindies |
| imprimatur | imprimaturs | imprimantur |
| matza | matzot | matzas |
| sergeant-major | sergeant-majors | sergeants-major |
| virago | viragos | viragoes |
| gendarme | gendarmes | gensdarmes |
| wildebeest | wildebeest | wildebeests |
| vertex | vertices | vertexes |
| sternum | sterna | sternums |
| cannula | cannulas | cannulae cannulæ |
| ala | alae | alæ |
| weirdo | weirdoes | weirdos |
| chili | chilis | chilies |
| taoiseach | taoiseachs | taoisigh |
| mantis | mantises | mantes |
| factum | facta | factums |
| crayfish | crayfishes | crayfish |
| miasma | miasmas | miasmata |
| carina | carinas | carinae |
| sarcoma | sarcomas | sarcomata |
| speculum | speculums | specula |
| hippopotamus | hippopotamuses | hippopotami hippopotamus |
| granary | granaries | granarys |
| gourami | gouramis | gouramies |
| mestizo | mestizos | mestizoes |
| doge | doges | dogi |
| codex | codices | codexes |
| plateful | platefuls | platesful |
| biogas | biogases | biogasses |
| pensione | pensiones | pensioni |
| archon | archontes | archons |
| calyx | calyces | calyxes |
| dybbuk | dybbuks | dybbukim |
| isthmus | isthmuses | isthmi |
| lux | lux | luxes |
| chlamydia | chlamydias | chlamydiae |
| simplex | simplexes | simplices |
| sturgeon | sturgeon | sturgeons |
| submatrix | submatrixes | submatrices |
| ibis | ibises | ibides |
| grosz | groszy | grosze |
| hatful | hatfuls | hatsful |
| neocortex | neocortices | neocortexes |
| albino | albinos | albinoes |
| fistula | fistulas | fistulae fistulæ |
| travail | travails | travaux |
| oblast | oblasts | oblasti |
| hundredweight | hundredweight | hundredweights |
| tyrannosaurus | tyrannosauri | tyrannosauruses |
| fez | fezzes | fezes |
| arpeggio | arpeggios | arpeggi |
| samara | samaras | samarae |
| matador | matadores | |
| lungfish | lungfish | lungfishes |
| cyclops | cyclops | cyclopes cyclopses |
| bonefish | bonefish | bonefishes |
| thumbs-up | thumbs-ups | thumbs-up |
| cerebellum | cerebellums | cerebella |
| mage | magi | mages |
| phalanx | phalanxes | phalanges |
| regnum | regnums | regna |
| loggia | loggias | logge loggie |
| optimum | optima | optimums |
| waldo | waldos | waldoes |
| gastroenteritis | gastroenterites | gastroenteritides |
| cay | cays | cayes |
| poof | poofs | pooves |
| ranunculus | ranunculuses | ranunculi |
| proboscis | proboscises | proboscides |
| residuum | residuums | residua |
| valor | valors | lbl |
| equinox | equinoxes | equinoctes |
| cholecystitis | cholecystites | cholecystitides |
| barracuda | barracuda | barracudas |
| butterflyfish | butterflyfishes | butterflyfish |
| myeloma | myelomas | myelomata |
| vertebra | vertebræ | vertebrae vertebras |
| peritonitis | peritonitides | peritonites |
| sandgrouse | sandgrouse | sandgrouses |
| nonzero | nonzeroes | nonzeros |
| dux | duxes | duces |
| spatula | spatulas | spatulae spatulæ |
| planetarium | planetariums | planetaria |
| dilettante | dilettanti | dilettantes |
| mojo | mojos | mojoes |
| via | vias | viae |
| trattoria | trattorias | trattorie |
| gateau | gateaus | gateaux |
| shelduck | shelducks | shelduck |
| gesso | gessos | gessoes |
| senor | senors | senores |
| necropolis | necropolises | necropoleis necropoles |
| lew | lews | lewis leois |
| nautilus | nautiluses | nautili |
| silverfish | silverfish | silverfishes |
| platypus | platypus platypi platypodes | |
| hyena | hyenas | hyena hyenae |
| soma | somas | somata |
| halibut | halibuts | halibut |
| mullet | mullets | mullet |
| pistachio | pistachios | pistachioes |
| maxilla | maxillas | maxillae maxillæ |
| colloquium | colloquiums | colloquia |
| otitis | otitides | otitises |
| grayling | grayling | graylings |
| zeitgeist | zeitgeists | zeitgeister zeitgeisten |
| pylorus | pylori | pyloruses |
| honorarium | honorariums | honoraria |
| conch | conches | conchs |
| tibia | tibias | tibiae |
| cranium | craniums | crania |
| gulden | guldens | gulden |
| hello | hellos | helloes |
| woonerf | woonerfs | woonerven |
| ptarmigan | ptarmigan | ptarmigans |
| coypu | coypus | coypu |
| firstborn | firstborn | firstborns |
| arbor | arbors | arbores |
| monkfish | monkfish | monkfishes |
| alluvium | alluviums | alluvia |
| kibbutz | kibbutzim | kibbutzes |
| collegium | collegia | collegiums |
| pupa | pupas | pupae pupæ |
| distaff | distaffs | distaves |
| coryza | coryzas | coryzae coryzæ |
| haiku | haiku | haikus |
| krill | krill | krills |
| bijou | bijous | bijoux |
| keiretsu | keiretsus | keiretsu |
| tarantula | tarantulas | tarantulae |
| sprat | sprat | sprats |
| brant | brants | brant |
| dogfish | dogfish | dogfishes |
| elk | elk | elks |
| dodman | dodmans | dodmen |
| pharynx | pharynges | pharynxes |
| kama | kama | kamas |
| dildo | dildos | dildoes |
| fovea | foveas | foveae foveæ |
| amoeba | amoebae | amoebas |
| yeti | yeti | yetis |
| novella | novellas | novelle |
| alpaca | alpacas | alpaca |
| omicron | omicrons | omicra |
| paco | pacos | pacoes |
| poltergeist | poltergeists | poltergeister |
| manga | manga | mangas |
| molybdenum | molybdenums | molybdena |
| scapula | scapulas | scapulae |
| toro | toros | toro |
| ordo | ordines | ordos |
| zona | zonas | zonae zonæ |
| insula | insulas | insulae |
| lionfish | lionfish | lionfishes |
| albedo | albedos | albedoes |
| junto | juntos | juntoes |
| kerchief | kerchiefs | kerchieves |
| deni | deni | denis |
| zebrafish | zebrafishes | zebrafish |
| mongoose | mongooses | mongeese |
| phlox | phlox | phloxes |
| bonito | bonito | bonitos bonitoes |
| tonsillitis | tonsillitides | tonsillites |
| pfennig | pfennige | pfennigs |
| bucketful | bucketfuls | bucketsful |
| simulacrum | simulacrums | simulacra |
| adieu | adieux | adieus |
| submucosa | submucosas | submucosae |
| naira | nairas | naira |
| aficionado | aficionados | aficionadoes aficionadi |
| amenorrhoea | amenorrhoeae | amenorrhoeas |
| rancho | ranchos | ranchoes |
| roomful | roomfuls | roomsful |
| goby | goby | gobies |
| amphora | amphorae | amphoras |
| coalfish | coalfishes | coalfish |
| pomfret | pomfret | pomfrets |
| semicolon | semicolons | semicola |
| sinfonietta | sinfoniettas | sinfoniette |
| foramen | foramina | foramens |
| armadillo | armadillos | armadilloes |
| rhombus | rhombi | rhombuses |
| cran | crans | cran |
| turbot | turbot | turbots |
| tympanum | tympanums | tympana |
| swearing-in | swearings-in | swearing-ins |
| gaijin | gaijin | gaijins |
| triceps | triceps | tricepses |
| coloratura | coloratura | coloraturas |
| retinoblastoma | retinoblastomas | retinoblastomata |
| chiaroscuro | chiaroscuros | chiaroscuri |
| phoney | phoneys | phonies |
| ostinato | ostinatos | ostinati |
| hyperbola | hyperbolas | hyperbolae hyperbolæ |
| encomium | encomiums | encomia |
| plectrum | plectrums | plectra |
| rumen | rumina | rumens |
| thalamus | thalami | thalamuses |
| daimyo | daimyo | daimyos |
| ancona | anconas | ancone |
| flatfish | flatfish | flatfishes |
| shekel | shekels | shekalim |
| tsetse | tsetses | tsetse |
| loa | loas | loa |
| weltanschauung | weltanschauungs | weltanschauungen |
| osteoarthritis | osteoarthritides | osteoarthritises |
| apparatchik | apparatchiks | apparatchiki |
| myocardium | myocardiums | myocardia |
| divertimento | divertimentos | divertimenti |
| farrago | farragos | farragoes |
| kanji | kanji | kanjis |
| crustacean | crustaceans | crustacea |
| oryx | oryxes | oryx |
| markka | markkas | markkaa |
| pizzeria | pizzerias | pizzerie |
| pizzicato | pizzicatos | pizzicati |
| glassfish | glassfishes | glassfish |
| boxful | boxfuls | boxesful |
| baht | baht | bahts |
| atheroma | atheromas | atheromata |
| pianoforte | pianofortes | pianoforti |
| ulna | ulnae | ulnas |
| prosciutto | prosciutti | prosciuttos |
| skinful | skinfuls | skinsful |
| curtsey | curtsies | curtseys |
| euro | euros | euro |
| arthropod | arthropods | arthropodae |
| polyanthus | polyanthuses | polyanthi |
| tyro | tyros | tyroes |
| flunkey | flunkeys | flunkies |
| capriccio | capriccios | capricci |
| ignoramus | ignoramuses | ignorami |
| niello | niellos | nielli |
| pianissimo | pianissimos | pianissimi |
| proscenium | prosceniums | proscenia |
| trousseau | trousseaus | trousseaux |
| glans | glans | glandes |
| zemstvo | zemstvos | zemstva |
| gyrus | gyri | gyruses |
| grouper | groupers | grouper |
| wacko | wackos | wackoes |
| whitey | whiteys | whities |
| fossa | fossae | fossæ |
| orca | orcas | orca |
| parenchyma | parenchymas | parenchymata |
| crowfoot | crowfoots | crowfeet |
| desperado | desperadoes | desperados |
| nasturtium | nasturtiums | nasturtia |
| imago | imagines | imagos imagoes |
| corolla | corollas | corollae corollæ |
| pyrexia | pyrexias | pyrexiae |
| koruna | korun | korunas koruny |
| albumen | albumens | albumina |
| cloaca | cloacas | cloacae |
| ulu | ulus | uluit |
| glissando | glissandi | glissandos glissandoes |
| geisha | geisha | geishas |
| pilchard | pilchard | pilchards |
| caput | caputs | capita |
| premaxilla | premaxillas | premaxillae |
| trapezius | trapezii | trapeziuses |
| quaich | quaichs | quaiches |
| medulla | medullas | medullae medullæ |
| killifish | killifishes | killifish |
| wino | winos | winoes |
| kris | krises | krisses |
| sailfish | sailfishes | sailfish |
| sackful | sackfuls | sacksful |
| senhor | senhors | senhores |
| meatus | meatus | meatuses |
| eyas | eyases | eyasses |
| graben | grabens | graben |
| tankful | tankfuls | tanksful |
| convolvulus | convolvuluses | convolvuli |
| lasso | lassos | lassoes |
| chorea | choreas | choreae choreæ |
| tetrahedron | tetrahedrons | tetrahedra |
| shad | shad | shads |
| apnoea | apnoeas | apnoeae |
| paterfamilias | paterfamiliases | patresfamilias |
| liang | liangs | liang |
| nephritis | nephritides | nephritises |
| houseful | housefuls | housesful |
| thumbs-down | thumbs-downs | thumbs-down |
| impala | impalas | impala |
| intaglio | intagli | intaglios intaglioes intaglii |
| cuttlefish | cuttlefishes | cuttlefish |
| gingivitis | gingivitides | gingivites |
| erythema | erythemas | erythemata |
| pers. | pers. | pers's |
| cicada | cicadas | cicadae |
| sura | suras | suwar |
| contango | contangos | contangoes |
| dazibao | dazibaos | dazibao |
| arista | aristae | aristas |
| cun | cuns | cun |
| eyeful | eyefuls | eyesful |
| vaquero | vaqueros | vaqueroes |
| cadenza | cadenzas | cadenze |
| earful | earfuls | earsful |
| toccata | toccatas | toccate |
| matzo | matzos | matzot matzoth |
| duckweed | duckweeds | duckweed |
| lying-in | lying-ins | lyings-in |
| kohlrabi | kohlrabis | kohlrabies |
| haematoma | haematomas | haematomata haematomae |
| rete | retes | retia |
| denarius | denarii | denariuses |
| impetigo | impetigos | impetigoes impetigines |
| umwelt | umwelts | umwelten |
| cupful | cupfuls | cupsful |
| excursus | excursuses | excursus |
| gaucho | gauchos | gauchoes |
| scoria | scorias | scoriae |
| shuriken | shurikens | shuriken |
| obbligato | obbligatos | obbligati |
| granuloma | granulomas | granulomata |
| mycoplasma | mycoplasmas | mycoplasmata |
| scriptorium | scriptoria | scriptoriums |
| pentathlon | pentathlons | pentathla |
| pocketful | pocketsful | pocketfuls |
| castrato | castratos | castrati |
| antipasto | antipastos | antipasti |
| yellowfin | yellowfin | yellowfins |
| cholangiocarcinoma | cholangiocarcinomas | cholangiocarcinomata |
| coulis | coulis | coulises |
| lasagna | lasagnas | lasagne |
| onomatopoeia | onomatopoeias | onomatopoeiae |
| kudu | kudus | kudu |
| cloverleaf | cloverleafs | cloverleaves |
| novena | novenas | novenae |
| heavy | heavies | heavys |
| flagstaff | flagstaffs | flagstaves |
| prostatitis | prostatitides | prostatites |
| mantissa | mantissas | mantissae |
| rhyton | rhytons | rhyta |
| ryokan | ryokans | ryokan |
| lamia | lamias | lamiae |
| tendonitis | tendonitises | tendonitides |
| topos | topoi | toposes |
| savoyard | savoyardi | savoyards |
| hobo | hobos | hoboes |
| lungful | lungfuls | lungsful |
| hadith | hadith | hadiths ahadith |
| meniscus | meniscuses | menisci |
| hidalgo | hidalgos | hidalgoes |
| forkful | forkfuls | forksful |
| patella | patellas | patellae |
| gutta | guttae | guttas |
| ilex | ilexes | ilices |
| icosahedron | icosahedra | icosahedrons |
| regulus | reguli | reguluses |
| lycopodium | lycopodiums | lycopodia |
| gnu | gnus | gnu |
| hepatoma | hepatomas | hepatomata |
| thrips | thrips | thripses |
| vomica | vomicas | vomicae |
| megahertz | megahertz | megahertzes |
| kittiwake | kittiwake | kittiwakes |
| kulak | kulaks | kulaki |
| abscissa | abscissas | abscissae abscissæ |
| ampulla | ampullas | ampullae |
| bolas | bolases | bolas |
| ibex | ibex | ibexes ibices |
| tela | telas | telae |
| imbroglio | imbroglios | imbrogli |
| muhajir | muhajireen | muhajirun |
| endocarditis | endocarditides | endocarditises |
| conquistador | conquistadors | conquistadores |
| magisterium | magisteriums | magisteria |
| kwacha | kwacha | kwachas |
| hisself | theirselves | |
| conjunctivitis | conjunctivitides | conjunctivitises conjunctivites |
| hwan | hwans | hwan |
| effluvium | effluvia | effluviums |
| upsilon | upsilons | upsila |
| lowlife | lowlifes | lowlives |
| druse | druses | drusen |
| verruca | verrucas | verrucae |
| jack-in-the-box | jacks-in-boxes | jacks-in-the-boxes jack-in-the-boxes jacks-in-the-box |
| octahedron | octahedra | octahedrons |
| sunfish | sunfish | sunfishes |
| callus | calluses | calli |
| dolphinarium | dolphinariums | dolphinaria |
| bredda | breddas | bredren |
| neuroblastoma | neuroblastomas | neuroblastomata |
| fogey | fogies | fogeys |
| shovelful | shovelfuls | shovelsful |
| sifu | sifu | sifus |
| dodecahedron | dodecahedra | dodecahedrons |
| shintiyan | shintiyans | shintiyan |
| fandango | fandangos | fandangoes |
| amaretto | amarettos | amaretti |
| matai | matais | matai |
| tilapia | tilapias | tilapia |
| vaginitis | vaginitides | vaginitises |
| prothorax | prothoraxes | prothoraces |
| dragoman | dragomans | dragomen |
| blastula | blastulas | blastulae |
| basso | bassos | bassi |
| occiput | occipita | occiputs |
| sacrum | sacra | sacrums |
| pardo | pardos | pardoes |
| hullo | hullos | hulloes |
Note: these words have been obtained from Wiktionary and have been classified and improved through automated computer linguistics processes.