This is a selection of words in CSW that you might expect to take a plural -S but which in fact do not. Such words can be categorised as:
1. singular nouns that do not inflect in the plural, as is the case with, for example, some Japanese words. Note that to keep the list manageable I have not attempted to cover the several thousand singular nouns that do have a plural form which just happens not to be -S. For example, the plural of TIMPANO is TIMPANI not TIMPANOS*, but at least it does have a plural that is different from the singular, and so is not included here.
2. plural nouns whose form might fool you into thinking they were singular e.g. KYNE, LOCHIA, OTAKU. This is a fairly subjective set of inclusions and I have assumed a modicum of Latin/Greek knowledge on the part of the reader e.g. enough to know that RADII is not a singular noun so no RADIIS*
3. words which look very like nouns but are in fact adjectives e.g. RATBITE. Again this is a fairly subjective set of inclusions
4. interjections that don't take S e.g. EEK, HUH, JOKOL: some interjections do pluralise and some don't, and no rule can be given
I have omitted words of more than 10 letters.
Now updated for CSW19. New words, if any, and new inflections of existing words, are shown in red.
| abram | adj | (Shakesp.) auburn. |
| accused | n | A person accused. |
| adnexa | npl | Conjoined anatomical parts. |
| aggri | npl | Ancient W. African variegated glass beads. |
| aha | int | Expressing exultation or pleasure. |
| ahem | int | A sound expressing delicate interruption. |
| alfredo | adj | Cooked with a cheese and egg sauce. |
| amadoda | npl | (Nguni) grown men. |
| angola | adj | Relating to a fabric made from the wool of the Angora goat. |
| antidora | npl | (Lat.) the unconsecrated bread remaining after the Eucharistic Liturgy, blessed by the priests and given to non-communicants as well as communicants. |
| apgar | adj | As in APGAR score, a system for determining the condition of an infant at birth. |
| arriba | int | Expressing pleasure or approval. |
| att | n | A Laotian monetary unit. |
| aue | n | (Maori) an exclamation of pain, distress or astonishment. |
| azerty | adj | A European version of the typewriter keyboard. |
| azo | adj | containing nitrogen |
| ballotini | npl | (Ital.) small glass beads used in reflective paint. |
| bandaid | adj | (Tradename) referring to a type of sticking-plaster. |
| bangalore | adj | As in bangalore torpedo, an explosive device in a long metal tube, used for blowing holes in barbed wire. |
| barro | adj | Embarrassing. |
| basho | n | (Japanese) in sumo wrestling, a tournament. |
| batwing | adj | As in batwing sleeve: a sleeve with a deep armhole and a tight cuff. |
| bedu | n | A tent-dwelling nomadic Arab. |
| bellcast | adj | Designating a style of roof architecture. |
| berbice | adj | As in berbice chair, a type of armchair with long arms that can be folded inwards to act as leg rests. |
| berko | adj | Berserk. |
| bigstick | adj | Of or relating to irresistible military strength. |
| bigtime | adj | Important. |
| bimble | adj | (Aborig.) as in bimble box, a type of dense Australian tree. |
| birchbark | adj | Made of birch bark, as in birchbark canoe. |
| bitou | adj | As in bitou bush, a sprawling woody South African shrub. |
| bliksem | adj | Expressing surprise. |
| bon | adj | (French) good |
| bona | npl | (Lat.) goods. |
| bonjour | int | (Fr.) good day. |
| bonsoir | int | (Fr.) good evening. |
| booshit | adj | Excellent. |
| borlotti | npl | (Ital.) as in borlotti bean, a variety of kidney bean. |
| borna | adj | As in borna disease, a type of viral disease. |
| bottomset | adj | As in bottomset bed, fine sediment deposited at the foot of a growing delta. |
| bowie | adj | As in bowie knife, a type of hunting knife. |
| buffel | adj | As in buffel grass, grass used for pasture in Africa etc. |
| bullosa | n | A genetic skin disorder. |
| bunde | n | A German federation or league. |
| bursera | adj | Designating a tropical American genus of trees yielding elemi and timber. |
| cajun | adj | (Fr.) relating to descendants of the French-speaking Acadians deported to Louisiana in 1755. |
| campeachy | adj | As in campeachy wood, a kind of logwood. |
| canneloni | npl | (Ital.) pasta in the shape of tubes, which are usually stuffed. |
| cardan | adj | As in cardan joint, a type of universal joint. |
| carrick | adj | As in carrick bend, a type of knot. |
| carron | adj | As in carron oil, an ointment of limewater and linseed oil. |
| cartop | adj | Able to fit on top of a car. |
| cattle | npl | Domesticated bovines. |
| centu | n | A Lithuanian monetary unit. |
| cevapcici | npl | (Yugoslavian) kebabs of minced beef and pork flavoured with mint and paprika. |
| chantilly | adj | (Fr.) as in chantilly lace, a type of ornamental lace. |
| charlier | adj | As in charlier shoe, a special light horseshoe. |
| cheval | adj | As in cheval glass, a full-length mirror that can be swivelled. |
| chimo | int | (Canadian) an Eskimo word used as greeting. |
| chinese | n | (Coll.) a Chinese meal. |
| chylde | n | A youth of gentle birth, esp. in ballads. |
| cimelia | npl | (Lat.) treasures laid up in store. |
| colorado | adj | Referring to a medium strength of cigar. |
| copataine | adj | Of a hat, high-crowned like a sugar loaf. |
| cremant | adj | Of wine, moderately sparkling. |
| cucking | adj | (Hist.) as in cucking stool, a kind of ducking stool for witches. |
| cunabula | npl | (Lat.) the place where something began or was nurtured. |
| curli | npl | Curled hairlike processes on the E. coli bacteria. |
| curule | adj | Of high authority, as a higher Roman magistrate who was entitled to a curule chair, one like a camp-stool with curved legs. |
| cyano | adj | Blue or dark blue. |
| dadchelor | adj | as in dadchelor party, a party primarily attended by men and held to honour and present gifts to a prospective father. |
| dataflow | adj | As in dataflow architecture. |
| dayglo | adj | (Tradename) of a luminous green, yellow, pink or orange. |
| deathcare | adj | Of, relating to, or providing products or services for the burial or cremation of the dead. |
| dirigiste | adj | (Fr.) relating to State control of economic and social affairs. |
| diriment | adj | That renders absolutely void; nullifying. |
| disodium | adj | Of a chemical compound containing sodium. |
| draco | adj | As in draco lizard, a flying lizard. |
| ducdame | int | (Shakesp.) a meaningless refrain. |
| eek | int | An interjection expressing fright. |
| elhi | adj | (US) pertaining to school grades 1 to 12. This is an adjective: |
| euoi | int | (Greek) a cry expressing Bacchic frenzy. |
| evoe | int | (Greek) a cry expressing Bacchic frenzy. |
| evhoe | int | (Greek) a cry expressing Bacchic frenzy. |
| evohe | int | (Greek) a cry expressing Bacchic frenzy. |
| fap | adj | drunk |
| farfalle | npl | Pasta in bow shapes. |
| fenning | noun | a monetary unit of Bosnia and Herzegovina. |
| fie | int | An interjection expressing reproach. |
| filmgoing | adj | Designating someone who goes to films e.g. the filmgoing public. |
| finnesko | n | (Norwegian) a reindeer-skin boot with the hair on. |
| finnsko | n | (Norwegian) a reindeer-skin boot with the hair on. |
| finsko | n | (Norwegian) a reindeer-skin boot with the hair on. |
| fisherfolk | n | People who fish especially for a living. |
| floatcut | adj | As in floatcut file, a file with parallel rows of teeth. |
| foefie | adj | as in foefie slide, a rope, fixed at an incline, along which a person suspended on a pulley may traverse a space, esp across a river. |
| freefall | adj | as in freefall parachuting |
| freewill | adj | Voluntary. |
| frenne | adj | (Spenser) foreign, strange. |
| fy | int | An interjection expressing reproach. |
| gaijin | n | (Japanese) a term for a foreigner. |
| galanty | adj | As in galanty show, a pantomime shadow play. |
| gandy | adj | As in gandy dancer, a railway track maintenance worker. |
| gateleg | adj | A style of table. |
| geronimo | int | A shout given by US paratroopers as they jump into battle. |
| gidday | int | An expression of greeting. |
| giltwood | adj | Made of wood and covered with gilt. |
| goldtail | adj | As in goldtail moth, a European moth with a yellow tail tuft. |
| gospoda | n | (Russian) a Russian title of address, equivalent to Mr. |
| gospodin | n | (Russian) a Russian title of address, equivalent to Mr. |
| grissini | npl | (Ital.) thin crisp breadsticks. |
| grubstreet | adj | relating to hack literature. |
| gullwing | adj | Of a vehicle door, opening upwards. |
| hadaway | int | An interjection urging someone on. |
| haikai | npl | (Japanese) a series of linked haiku. |
| haith | int | (Scots) interj. by my faith! |
| halfen | n | (Spenser) half. |
| halfpence | n | Coins worth half a penny. |
| heame | n | (Spenser) home. |
| heigh | int | A cry of enquiry, encouragement. |
| heishi | npl | (Japanese) tiny beads made from shells. |
| hic | int | Representing a hiccup. |
| hillfolk | n | People living among the hills. |
| hiphugger | adj | Of trousers, having a low waist. |
| hoka | n | (Maori) red cod. |
| hokku | npl | (Japanese) a series of haiku. |
| howzat | int | A cry in cricket appealing for dismissal of batsman. |
| howzit | int | A greeting. |
| huh | int | Interj. expressing non-understanding. |
| hwan | n | A monetary unit of S. Korea. |
| inro | n | (Japanese) a small container for pills and medicines. |
| inshallah | int | (Arabic) an interjection among Muslims: if Allah wills. |
| ither | adj | Other. |
| ivyleaf | adj | as in ivyleaf geranium. |
| jai | int | (Hindi) victory (to). |
| jillionth | adj | The ordinal of JILLION. |
| jinne | int | An interjection expressing surprise, shock etc. |
| jirre | int | An interjection expressing surprise, shock etc. |
| jokol yokul | int | (Obs.) (Shetlands) yes (literally yes, carl i.e. yes, fellow). |
| jonnock | adj | Honest. |
| jun | n | A coin of North Korea. |
| kaal | adj | (S. Afr.) naked. |
| kam | adj | (Shakesp.) crooked, awry |
| kasme | int | (Hinglish) I swear. |
| kerchoo | int | An interjection expressing a sneeze. |
| kernmantel | adj | Denoting a type of mountaineering rope. |
| keto | adj | Pertaining to KETONE, a chemical compound of carbon, obtained by distilling salts of organic acids. |
| kidglove | adj | As in kidglove treatment. |
| kiff | adj | (S. Afr.) excellent. |
| kirby | adj | As in kirby grip, a grip for the hair. |
| kneejerk | adj | As in kneejerk reaction. |
| kokobeh | adj | Of certain fruit, having a rough skin. |
| kongoni | n | (Swahili) an E. African hartebeest. |
| kreplach | n | (Yiddish) small dough dumplings usu. served in soup. |
| kreplech | n | (Yiddish) small dough dumplings usu. served in soup. |
| kueh | n | (Malay) any cake of Malay, Chinese or Indian origin. |
| kumbaloi | npl | (Greek) worry beads. |
| ky | npl | Cattle. |
| kyne | npl | (Spenser) kine, cattle. |
| lakeview | adj | Overlooking a lake. |
| laquearia | n | (Lat.) a ceiling consisting of panelled recessed compartments |
| leafcutter | adj | As in leafcutter ant. |
| lebkuchen | n | (Ger.) a biscuit containing honey and spices. |
| lehrjahre | npl | (Ger.) an apprenticeship. |
| leopardskin | adj | Made from the skin of a leopard. |
| leu | n | A unit of Romanian currency. |
| lifehold | adj | Of land, held by a life estate. |
| lightwave | adj | Relating to a wave of light. |
| lokshen | npl | (Yiddish) noodles. |
| longcase | adj | As in longcase clock, a grandfather clock. |
| lor | int | expressing surprise |
| lossmaking | adj | Making a loss, as in a lossmaking enterprise. |
| lyra | adj | As in lyra viol, a lute-like instrument forerunner of the mandolin. |
| macrobiota | npl | The larger organisms in the soil. |
| magyar | adj | (Hungarian) of a garment, cut with the sleeves in a piece with the rest. |
| malibu | adj | As in malibu board, a lightweight surfboard. |
| malist | v | (Spenser) pp. of MALICE, to bear ill-will towards. |
| manet | int | (Lat.) a stage direction: he or she remains on stage. |
| manriding | adj | Designating equipment on oil rigs that is for use of personnel rather than for carrying material. |
| marchen | noun | (Germ.) a folk tale or fable. |
| marengo | adj | (Ital.) designating a dish browned in oil and sauteed in mushrooms, tomatoes, onions and white wine. |
| mazeltov | int | (Yiddish) congratulations. |
| menshen | n | (Chinese) a Chinese door god. |
| meuniere | adj | (Fr.) (of food, esp. fish) lightly coated in flour and fried in butter. |
| midshore | adj | Designating a fishery that is between the inshore and offshore fisheries. |
| mim | adj | prim and proper |
| mixte | adj | Denoting a type of bicycle frame. |
| moai | n | (Rapanui) any of the gigantic stone statues of Easter Island. |
| murdabad | int | (Urdu) death to, used in slogans. |
| musha | int | (Irish) an interjection expressing surprise. |
| nanoscale | adj | On a very small scale. |
| nassella | adj | As in nassella tussock, a type of tussock grass. |
| nisi | adj | (Lat.) taking effect at a specified date unless cause is shown otherwise. |
| nogaku | n | (Japanese) a traditional Japanese style of drama, aka NOH. |
| noh | n | A traditional style of Japanese drama. |
| nontarget | adj | Describing something that is not a target. |
| novalia | npl | In Scots law, waste lands newly reclaimed. |
| omniana | npl | (Lat.) about all sorts of things. |
| organotin | adj | Of an organic compound used as a pesticide. |
| ovipara | npl | An artifical division of vertebrates, including those that lay eggs. |
| paravail | adj | below others in rank e.g. a tenant paravail |
| paravant | adj | before, in front |
| passager | adj | As in passager hawk, a young hawk or falcon caught on migration. |
| phew | int | An exclamation of relief, astonishment etc. |
| pice | n | (Hindi) an Indian coin, 1/4 anna. |
| pirojki | n | (Russian) a small Russian pastry made with meat or cabbage filling. |
| piroshki | n | (Russian) a small Russian pastry made with meat or cabbage filling. |
| pirozhki | n | (Russian) a small Russian pastry made with meat or cabbage filling. |
| polyacid | adj | Designating a compound with more than one acidic group |
| popeseye | adj | Denoting a cut of steak. |
| proface | int | (Shakesp) may it profit you, a phrase of welcome |
| prosit | int | (Lat.) a toast to good health. |
| prost | int | (Lat.) a toast to good health. |
| pugh | int | (Obs.) pooh, an expression of contempt. |
| puh | int | (Obs.) pooh, an expression of contempt. |
| quep | int | (Obs.) an interjection expression remonstrance. |
| rappen | n | (Ger.) a monetary unit of Switzerland. |
| rappini | npl | (Ital.) immature turnip plants. |
| raree | adj | As in raree show, a street show or carnival. |
| ratbite | adj | As in ratbite fever, an acute infectious disease caught from the bite of a rat. |
| rikishi | n | (Japanese) a sumo wrestler. |
| rokkaku | n | (Japanese) a Japanese fighting kite. |
| rusticana | npl | Objects such as agricultural implements, garden furniture etc made in the rustic style. |
| sagrada | adj | (Spanish) as in cascara sagrada, dried bark of the cascara buckthorn, used as a purgative. |
| santimu | n | (Latvian) a former coin of Latvia. |
| satem | adj | A classification group of Indo-European languages, in which an original palatal consonant developed as a sibilant |
| sau | n | A Vietnamese coin. |
| seelie | npl | Good benevolent fairies. |
| semilog | adj | Having an arithmetic scale of the x-axis and a logarithmic scale of the y-axis. |
| sengi | n | A monetary unit of Zaire. |
| senryu | n | (Japanese) a 3-line Japanese poem. |
| senti | n | A former monetary unit of Tanzania. |
| shagpile | adj | Of carpets, having a pile of long thick fibres. |
| sharon | adj | As in sharon fruit, persimmon. |
| shazam | int | (Tradename) a magic slogan. |
| shen | noun | the spiritual element of a person's psyche. |
| shojo | noun | manga for girls. |
| shortcrust | adj | Designating a type of pastry. |
| sidh | npl | (Irish) fairy people. |
| sidhe | npl | (Irish) fairy people. |
| signeur | adj | (Shakesp.) senior. |
| siroset | adj | Of or relating to the chemical treatment of woollen fabrics to give a permanent-press effect. |
| sitka | adj | As in sitka spruce, a tall N. American spruce tree. |
| sleepaway | adj | Relating to a camp for teenagers. |
| soho | int | (Shakesp.) a huntsman's halloo. |
| sokaiya | n | (Japanese) in Japan, a corporate racketeer. |
| solgel | adj | Relating to an alternation between SOL and GEL states. |
| sorbo | adj | As in sorbo rubber, a spongy form of rubber. |
| spaza | adj | (S. Afr.) as in spaza shop, a small shop in a township. |
| staghorn | adj | As in staghorn fern, a type of fern with fronds that resemble antlers. |
| strokeplay | adj | Referring to scoring by counting the total number of strokes played (rather than the number of holes won). |
| stunkard | adj | (Scots) sulky, sullen |
| subaudio | adj | Relating to low-frequency audio. |
| suboval | adj | Somewhat oval; nearly oval. |
| subsea | adj | Below the surface of the sea. |
| tachina | adj | As in tachina fly, bristly fly. |
| talaria | npl | (Lat.) small wings or winged shoes represented as fastened to the ankles, chiefly used as an attribute of Mercury or Hermes. |
| teenage | adj | Pertaining to teenagers. |
| teenybop | adj | Of or pertaining to TEENYBOPPERS. |
| tenesi | noun | a monetary unit of Turkmenistan. |
| tertium | adj | (Lat.) as in tertium quid, an unknown indefinite third thing. |
| thyine | adj | In biblical translations and allusions: of, pertaining to, or designating (the wood of) the thuya. |
| tompot | adj | as in tompot blenny, a kind of fish with tentacles over its eyes. |
| tonka | adj | (Tupi) as in tonka bean, a tall leguminous African tree with fragrant black almond-shaped seeds. |
| torii | n | (Japanese) a Shinto temple gateway. |
| tormina | npl | (Lat.) acute, colicky pains. |
| tother | adj | (Arch.) the other. |
| townfolk | npl | The people of a town. |
| townsfolk | npl | The people of a town. |
| trypan | adj | As in trypan blue, a blue dye obtained from tolidine. |
| tyin | n | A monetary unit of Kyrgyzstan. |
| uillean uilleann | adj | Denoting a kind of Irish bagpipes |
| umpteen | adj | Designating an indefinitely large number. |
| undead | n | A vampire. |
| unseelie | npl | Evil malevolent fairies. |
| vagrom | adj | (Shakesp.) vagrant. |
| verd | adj | As in verd antique, a dark green mottled impure variety of serpentine. |
| wardian | adj | As in wardian case, a type of glass container for housing delicate plants. |
| wayleggo | int | (NZ) a shepherd's call to his dog. |
| whee | int | An expression of delight. |
| willyard | adj | (Scots) wilful |
| willyart | adj | (Scots) wilful |
| wirra | int | An interjection expressing sorrow. |
| wotcha | int | A verbal salutation. |
| wotcher | int | A verbal salutation. |
| wowee | int | An interjection, an intensification of WOW. |
| wroth | adj | Wrathful; in commotion; stormy. |
| xu | n | A Vietnamese monetary unit. |
| yakuza | n | (Japanese) a Japanese gangster. |
| yokul | int | (Obs.) (Shetlands) yes (literally yes, carl i.e. yes, fellow). |
| zapata | adj | Denoting a kind of flowing, drooping moustache. |
| ziptop | adj | Having the top opening fastened with a zipper. |
| zite | npl | (Ital.) a type of pasta like large macaroni. |