Online Etymology Dictionary

nimby: acronym for not in my back yard, 1980, American English, supposedly coined by Walter Rodgers of the American Nuclear Society.
nimiety (n.): "excess, redundancy," from Latin nimietas "excessiveness," from nimius "beyond measure, excessive," from nimis (adv.) "too much, beyond measure, excessively."
Nimrod: "great hunter," 1712, a reference to the biblical son of Cush, referred to (Gen. x:8-9) as "a mighty hunter before the Lord." It came to mean "geek, klutz" by 1983 in teenager slang, for unknown reasons. (Amateur theories include its occasional use in "Bugs Bunny" cartoon episodes featuring rabbit-hunting Elmer Fudd as a foil; its possible ironic use, among hunters, for a clumsy member of their fraternity; or a stereotype of deer hunters by the non-hunting population in the U.S.)
Nimzo-Indian (adj.): type of defensive opening in chess, 1935, in reference to Aron Nimzowitsch (1886-1935), Latvian-born Jewish chess genius who popularized it, a variation of the Indian defense (late 19c.) attributed to Indian chess player Moheschunder Bannerjee.
Nina: fem. proper name; in a Russian context it is a shortening of Annina, diminutive of Greek Anna. In a Spanish context, Niña "child, infant," a nursery word.
nincompoop (n.): 1670s, nicompoop. Despite similarity [noted by Johnson] to Latin legal phrase non compos mentis "insane, mentally incompetent" (c.1600), the connection is denied by etymologists because the earliest forms lack the second -n-. Weekley thinks first element may be a proper name, and cites Nicodemus, which he says was used in French for "a fool," or Nicholas. Klein says probably an invented word.
nine (n.): Old English nigen, from Proto-Germanic *niwun (cf. Old Saxon nigun, Old Frisian niugun, Old Norse niu, Swedish nio, Middle Dutch neghen, Dutch negen, Old High German niun, German neun, Gothic niun "nine"), from PIE newn "nine" (cf. Sanskrit nava, Avestan nava, Greek ennea, Albanian nende, Latin novem (with change of -n- to -m- by analogy of septem, decem), Lithuanian devnyi, Old Church Slavonic deveti (the Balto-Slavic forms by dissimilation of -n- to -d-), Old Irish noin, Welsh naw).

Nine to five "the average workday" is attested from 1935. Nine days has been proverbial since 14c. for the time which a wonder or novelty holds attention.
ninefold: Old English nigonfeald; see nine + -fold.
ninepins (n.): 1570s, from nine + pin (n.). From the number of pins to be knocked down.
nines (n.): in phrase to the nines "to perfection" (1787) first attested in Burns, apparently preserves the ancient notion of the perfection of the number as three times three (e.g. the nine Muses, etc.
[T]he Book of St. Albans, in the sections on blasonry, lays great stress on the nines in which all perfect things (orders of angels, virtues, articles of chivalry, differences of coat armour, etc.) occur. [Weekley]
No one seems to consider that it might be a corruption and misdivision of to then anes, literally "for the one (purpose or occasion)," a similar construction to the one that yielded nonce (q.v.).
nineteen (n.): late Old English nigontiene; see nine + -teen.
nineteenth (adj.): late 14c., nyntenthe; from nineteen + -th. Replaced Old English nigon-teoða. Nineteenth hole "bar-room in a golf clubhouse" is attested from 1901.
nineties (n.): 1857 as the years of someone's life between 90 and 99; 1848 as a decade of years in a given century; 1849 with reference to Fahrenheit temperature. See ninety.
Many still live who remember those days; if the old men cannot tell you the exact date, they will say: 'It were in the nineties;' (etc.) ["Chambers's Journal," Nov. 1, 1856]
In Britain, the naughty nineties was a popular name 1920s-30s for the 1890s, based on the notion of a relaxing of morality and mood in contrast to earlier Victorian times. In U.S., gay nineties in reference to the same decade is attested from 1927, and was the title of a regular nostalgia feature in "Life" magazine about that time.
The long, dreary blue-law Sunday afternoons were periods of the Nineties which no amount of rosy retrospect will ever be able to recall as gay, especially to a normal healthy boy to whom all activities were taboo except G. A. Henty and the bound volumes of Leslie's Weekly of the Civil War. [Life, Sept. 1, 1927]
ninetieth: late 14c., nyntithe; see ninety + -th. Replaced Old English nigenteoþan.
ninety (n.): Old English nigontig, from nine + -tig "group of ten" (see -ty (1)). Cognate with Old Frisian niontich, Middle Dutch negentich, Dutch negentig, German neunzig.
ninny (n.): "simpleton, fool," 1590s, perhaps a misdivision of an innocent (see N for other examples), or from the pet form of the proper name Innocent, with sense influenced by the name's literal meaning. There may be some influence in the word of Italian ninno "baby, child."
ninnyhammer (n.): also ninny-hammer, "simpleton," 1590s, from ninny + hammer (n.), but the signification of the second element is obscure.
ninth (adj.): early 12c., nigonðe; see nine + -th. Replacing Old English nigoða, nigend.
Niobe: in Greek mythology, a queen of Thebes, daughter of Tantalus, changed to a stone while weeping for her children (slain, after she boasted of them overmuch, by Artemis and Apollo); hence the name is used figuratively for bereavement and woe. The name is said to mean literally "snowy; snowy-bright."
niobium: named by German scientist Heinrich Rose, who discovered it in 1844 in the mineral tantalum; so called because in Greek mythology Niobe was the daughter of Tantalus.
nip (n.2): "a pinch; a sharp bite," 1540s, from nip (v.). Meaning "a chill in the weather" is from 1610s, probably so called for its effect on vegetation. Nip and tuck "a close thing" is recorded from 1832, perhaps from sailing or tailoring.
nip (v.): "to pinch sharply; to bite suddenly," late 14c., related to Middle Low German nipen "to nip, to pinch," Middle Dutch nipen "to pinch," Dutch nijpen, Old Norse hnippa "to prod," but the exact evolution of the stem is obscure. Related: Nipped; nipping. To nip (something) in the bud in the figurative sense is first recorded c.1600.
nip (n.1): "small measure of spirits," 1796, shortening of nipperkin (1670s) "quantity of liquor of a half pint or less," possibly of Dutch or Low German origin and related to nip (v.). Reinforced by nip (n.2) on notion of "fragment or bit pinched off" (c.1600).
nipper (n.): "small boy," 1859, originally (1530s) a pickpocket who "pinched" other people's property; see nip (v.).
nipple (n.): 1530s, nyppell, "teat, duct-laden extremity of a mammalian breast," alteration of neble (1520s), probably diminutive of neb "bill, beak, snout" (see neb), hence, literally "a small projection." In reference to an artificial device on an infant's bottle, from 1875. A 16c.-17c. slang term for a woman's nipples was cherrilets.
Nipponese: "Japanese," 1859, from Nippon, Japanese word for "Japan," from ni(chi) "the sun" + pon, hon "source," which is said to be from Chinese for "rising sun-place." Derisive slang shortening Nip attested from 1942.
nippy (adj.): 1898, in reference to a "biting" chill in the air, from nip (n.2) + -y (2). Related: Nippiness.
nirvana (n.): 1836, from Sanskrit nirvana-s "extinction, disappearance" (of the individual soul into the universal), literally "to blow out, a blowing out" ("not transitively, but as a fire ceases to draw;" a literal Latinization would be de-spiration), from nis-, nir- "out" + va- "to blow" (see wind (n.1)). Figurative sense of "perfect bliss" is from 1895.
nisei (n.): "American born of Japanese parents," from Japanese ni- "second" + sei "generation." Use limited to U.S. West Coast until c.1942.
nit (n.): Old English hnitu "louse egg, nit," from Proto-Germanic *khnito (cf. Norwegian nit, Middle Dutch nete, Dutch neet, Middle High German niz, German Niß), from PIE root *knid- "egg of a louse" (cf. Russian, Polish gnida, Czech knida; Greek konidos, genitive konis "egg of a louse").
nite (n.): arbitrary respelling of night, attested from 1931.
niter: see nitre.
nitpick (v.): "seek petty faults," also nit-pick, 1962, back-formation from earlier nitpicker. Related: Nitpicking; nitpicky.
nitpicker (n.): "pedantic critic," 1951; see nit (n.) + pick (v.).
nitrate (n.): 1794, from French nitrate (1787) or formed in English from nitre + -ate (3). Related: Nitrates.
nitre (n.): c.1400, "native sodium carbonate," from Old French nitre (13c.), from Latin nitrum, from Greek nitron, which is possibly of Eastern origin (cf. Hebrew nether "carbonate of soda;" Egyptian ntr). Originally a word for native soda, but also associated from Middle Ages with saltpeter (potassium nitrate) for obscure reasons; this became the predominant sense by late 16c.
nitric (adj.): 1794, originally in reference to acid obtained initially from distillation of saltpeter; see nitre + -ic. Perhaps immediately from French nitrique. Known as aqua fortis, later acid spirit of nitre, then nitric acid. (1787) under the system ordered by Lavoisier.
nitrification (n.): 1827, from French nitrification (1787, de Morveau), from nitrifier (1777), from nitre (see nitre).
nitro (n.): abbreviation of nitroglycerine, 1935, slang.
nitro-: before vowels nitr-, word-forming element used scientifically and indicating "nitrogen, nitrate" or "nitric acid," from comb. form of Greek nitron (see nitre).
nitrogen (n.): 1794, from French nitrogène, coined 1790 by French chemist Jean Antoine Chaptal (1756-1832), from comb. form of Greek nitron "sodium carbonate" (see nitro-) + French gène "producing," from Greek -gen "giving birth to" (see -gen). The gas was identified in part by analysis of nitre. Earlier name (1772) was mephitic air, and Lavoisier called it azote (see azo-).
nitroglycerine (n.): also nitroglycerin, "explosive oily liquid," 1857, from nitro- + glycerin. So called either because it was obtained by treating glycerine with nitric and sulfuric acids or because it is essentially a nitrate (glyceryl trinitrate).
nitrous (adj.): c.1600, from Latin nitrosus, from nitrum (see nitre). Originally "of nitre, pertaining to nitre;" more precise use in chemistry (designating a compound in which the nitrogen has a lower valence than the corresponding nitric compound) is from 1780s. Nitrous oxide attested from 1800.
nitty (adj.): "full of nits," 1560s, from nit + -y (2).
nitty-gritty (n.): "basic facts," 1961, knitty-gritty, American English, said to have been chiefly used by black jazz musicians, perhaps ultimately from nit and grits "finely ground corn." As an adjective from 1966.
nitwit (n.): "stupid person," 1922, probably from nit "nothing," from dialectal German or Yiddish, from Middle Low German (see nix) + wit (n.).
nix (n.): "nothing, none," 1789, from German nix, dialectal variant of nichts "nothing," from Middle High German nihtes, from genitive of niht, nit "nothing," from Old High German niwiht, from ni, ne "no" (see un-) + wiht "thing, creature" (cf. naught).
nix (v.): "cancel, refuse, forbid," 1903, from nix (n.). Related: Nixed; nixing.
nixie (n.): "water fairy," 1816 (introduced by Sir Walter Scott), from German Nixie, from Old High German nihhussa "water sprite," fem. of nihhus, from Proto-Germanic *nikwiz (cf. Old Norse nykr, Old English nicor "water spirit, water monster," also used to gloss hippopotamus; Grendel's mother in "Beowulf" was a nicor), perhaps from PIE *neigw- "to wash" (cf. Sanskrit nenkti "washes," Greek nizo "I wash," Old Irish nigid "washes").
Nixon: surname, variant of Nickson, literally "son of (a man named) Nick, English familiar form of Nicholas.