Online Etymology Dictionary

nifty (adj.): "smart, stylish," 1868, of unknown origin, perhaps theatrical slang, first attested in a poem by Bret Harte, who said it was a shortened, altered form of magnificat. Related: Niftily; niftiness.
nig (n.): c.1300, "niggardly person" (see niggard). As an abbreviated form of nigger, attested by c.1832, American English.
nig-nog (n.): "foolish person," 1953, OED suggests from earlier cant slang nigmenog "a very silly fellow" (1700). As a term of abuse for a black person, a shortened and reduplicated form of nigger.
Nigel: masc. proper name; see Neil.
Niger: African nation, named for the river Niger, mentioned by that name 1520s (Leo Africanus), probably an alteration (by influence of Latin niger "black") of a local Tuareg name, egereou n-igereouen, from egereou "big river, sea" + n-igereouen, plural of that word. Translated in Arabic as nahr al-anhur "river of rivers."
Nigeria: African nation, named for river Niger, which runs through it, + -ia. Related: Nigerian.
nigga (n.): 1925, also niggah, representing southern U.S. pronunciation of nigger (q.v.).
niggard (n.): "mean person, miser," late 14c., nygart, of uncertain origin. The suffix suggests French origin (cf. -ard), but the root word is possibly from earlier nig "stingy" (c.1300), perhaps from a Scandinavian source related to Old Norse hnøggr "stingy," from Proto-Germanic *khnauwjaz (cf. Swedish njugg "close, careful," German genau "precise, exact"), and to Old English hneaw "stingy, niggardly," which did not survive in Middle English.
niggardly (adj.): 1560s, from niggard + -ly (1).
It was while giving a speech in Washington, to a very international audience, about the British theft of the Elgin marbles from the Parthenon. I described the attitude of the current British authorities as "niggardly." Nobody said anything, but I privately resolved -- having felt the word hanging in the air a bit -- to say "parsimonious" from then on. [Christopher Hitchens, "The Pernicious Effects of Banning Words," Slate.com, Dec. 4, 2006]
As an adverb from 1520s. Related: Niggardliness.
nigger (n.): 1786, earlier neger (1568, Scottish and northern England dialect), from French nègre, from Spanish negro (see Negro). From the earliest usage it was "the term that carries with it all the obloquy and contempt and rejection which whites have inflicted on blacks" [cited in Gowers, 1965, probably Harold R. Isaacs]. But as black inferiority was at one time a near universal assumption in English-speaking lands, the word in some cases could be used without deliberate insult. More sympathetic writers late 18c. and early 19c. seem to have used black (n.) and, after the American Civil War, colored person.
"You're a fool nigger, and the worst day's work Pa ever did was to buy you," said Scarlett slowly. ... There, she thought, I've said "nigger" and Mother wouldn't like that at all. [Margaret Mitchell, "Gone With the Wind," 1936]
Also applied by English settlers to dark-skinned native peoples in India, Australia, Polynesia. The reclamation of the word as a neutral or positive term in black culture (not universally regarded as a worthwhile enterprise), often with a suggestion of "soul" or "style," is attested first in the U.S. South, later (1968) in the Northern, urban-based Black Power movement.

Used in combinations (e.g. nigger-brown) since 1840s for various dark brown or black hues or objects; euphemistic substitutions (e.g. Zulu) began to appear in these senses c.1917. Brazil nuts were called nigger toes by 1896. Variant niggah, attested from 1925 (without the -h, from 1969), is found usually in situations where blacks use the word. Nigra (1944), on the other hand, in certain uses reflects a pronunciation of negro meant to suggest nigger, and is thus deemed (according to a 1960 slang dictionary) "even more derog[atory] than 'nigger.' " Slang phrase nigger in the woodpile attested by 1800; "A mode of accounting for the disappearance of fuel; an unsolved mystery" [R.H. Thornton, "American Glossary," 1912]. Nigger heaven "the top gallery in a (segregated) theater" first attested 1878 in reference to Troy, N.Y.
niggerhead (n.): from nigger + head. A term used formerly in U.S. of various things, e.g. "cheap tobacco" (1843), "protruding root mass in a swamp" (1859), a type of cactus (1877), and the black-eyed susan (1893). Variant negro-head attested from 1781.
niggle (v.): 1590s (implied in niggling), possibly from a Scandinavian source (cf. Norwegian dialectal nigla "be busy with trifles"), perhaps related to source of niggard. Related: Niggled; niggling; niggler.
nigh (adv.): "near," Old English neah (West Saxon), neh (Anglian), common Germanic (cf. Old Saxon nah, Old Frisian nei, Middle Dutch, Dutch na, Old High German nah, German nah, Gothic nehwa), with no cognates outside Germanic. The Old English progression was neah - near - niehsta, for "nigh - near - next." But the comparative near and the superlative nehst (see next) gradually evolved into separate words not felt as related to nigh. New comparative and superlative forms nigher, nighest developed 14c. as phonetic changes obscured the original relationships. As an adjective from Middle English.
night (n.): Old English niht (West Saxon neaht, Anglian næht, neht) "night, darkness;" the vowel indicating that the modern word derives from oblique cases (genitive nihte, dative niht), from Proto-Germanic *nakht- (cf. Old Saxon and Old High German naht, Old Frisian and Dutch nacht, German Nacht, Old Norse natt, Gothic nahts).

The Germanic words are from PIE *nekwt- "night" (cf. Greek nuks "a night," Latin nox, Old Irish nochd, Sanskrit naktam "at night," Lithuanian naktis "night," Old Church Slavonic nosti, Russian noch', Welsh henoid "tonight"), according to Watkins, probably from a verbal root *neg- "to be dark, be night." For spelling with -gh- see fight.
The fact that the Aryans have a common name for night, but not for day (q.v.), is due to the fact that they reckoned by nights. [Weekley]
Cf. German Weihnachten "Christmas." In early times, the day was held to begin at sunset, so Old English monanniht "Monday night" was the night before Monday, or what we would call Sunday night.

To work nights preserves the Old English genitive of time. Night shift is attested from 1710 in the sense of "garment worn by a woman at night" (see shift (n.1)); meaning "gang of workers employed after dark" is from 1839. Night soil "excrement" (1770) is so called because it was removed (from cesspools, etc.) after dark. Night train attested from 1838. Night life "habitual nocturnal carousing" attested from 1852.
night-hawk (n.): from 1610s in reference to various birds, from night + hawk (n.). Figurative sense of "one who stays up and is active at night" is from 1818.
night-light (n.): 1640s, "faint light visible in the sky at night," from night + light (n.). As "small light used in rooms at night to keep them from total darkness" from 1851.
night-night: nursery talk, "good-night," 1896; form nighty-night is attested from 1876.
night-owl (n.): "owl which flies at night," 1590s; applied since 1846 (American English) to persons who are up or out late at night. Cf. night-hawk, also French hirondelle de nuit "prostitute," literally "night-swallow."
night-watch (n.): "guard kept during the night," late Old English; see night + watch (n.).
night-work (n.): 1590s, from night + work (n.). Old English had nihtweorc.
nightcap (n.): also night-cap, late 14c., "covering for the head, worn in bed," from night + cap (n.). In the alcoholic sense, it is attested from 1818. American English sense of "final event in a sporting contest" (especially the second game of a baseball double-header) is from 1939.
nightclub (n.): also night-club, "club open at night," 1894, from night + club (n.) in the social sense.
nightfall (n.): 1700; see night + fall (n.).
nightgown (n.): also night-gown, c.1400, from night + gown.
nightie (n.): 1871, short for nightgown; originally a children's word.
nightingale (n.): Old English næctigalæ, nihtegale, compound formed in Proto-Germanic (cf. Dutch nachtegaal, German Nachtigall) from *nakht- "night" (see night) + *galon "to sing," related to Old English giellan "yell" (see yell). With parasitic -n- that appeared mid-13c. Dutch nightingale "frog" is attested from 1769. In Japanese, "nightingale floor" is said to be the term for boards that creak when you walk on them.
nightjar (n.): nocturnal bird, goatsucker, 1620s, from night + jar (v.). So called for the "jarring" sounds made by the male when the female is brooding, which have been described as a "churring trill that seems to change direction as it rises and falls." An Old English word for it was nihthræfn "night raven."
nightlong (adj.): Old English nihtlang; see night + -long.
nightly (adj.): Old English nihtlic "nocturnal, of the night, at night;" see night + -ly (1). As an adverb, Middle English nihtlich, from the adjective.
nightmare (n.): late 13c., "an evil female spirit afflicting sleepers with a feeling of suffocation," compounded from night + mare (3) "goblin that causes nightmares, incubus." Meaning shifted mid-16c. from the incubus to the suffocating sensation it causes. Sense of "any bad dream" first recorded 1829; that of "very distressing experience" is from 1831. Cognate with Middle Dutch nachtmare, German Nachtmahr.
nightmarish (adj.): 1834, from nightmare + -ish. Related: Nightmarishly; nightmarishness.
nightshade (n.): Old English nihtscada, literally "shade of night," perhaps in allusion to the poisonous berries. A common Germanic compound, cf. Dutch nachtschade, German Nachtschatten.
nightspot (n.): also night spot, "nightclub," 1936, from night (n.) + spot (n.) "place."
nightstick (n.): also night-stick, 1887, from night + stick (n.). So called because it was carried on night patrols.
nighttime (n.): also night-time, c.1400, from night + time (n.).
nigra: see nigger.
nihil (n.): Latin, literally "nothing" (see nil). Phrase nihil obstat "nothing stands in the way" printed on first pages of a Catholic work indicates its official approval.
nihilism (n.): 1817, "the doctrine of negation" (in reference to religion or morals), from German Nihilismus, from Latin nihil "nothing at all" (see nil), coined by German philosopher Friedrich Heinrich Jacobi (1743-1819). In philosophy, an extreme form of skepticism (1836). The political sense was first used by German journalist Joseph von Görres (1776-1848). Turgenev used the Russian form of the word (nigilizm) in "Fathers and Children" (1862) and claimed to have invented it. With a capital N-, it refers to the Russian revolutionary anarchism of the period 1860-1917, supposedly so called because "nothing" that then existed found favor in their eyes.
nihilist (n.): 1836 in the religious or philosophical sense, from French nihiliste, from Latin nihil (see nihilism). In the Russian political sense, it is recorded from 1871. Related: Nihilistic.
nihility (n.): 1670s, from Medieval Latin nihilitas, from nihil "nothing at all" (see nil).
Nike: Greek goddess of victory (identified by the Romans with their Victoria), literally "victory," probably connected with neikos "quarrel, strife," neikein "to quarrel with." As a type of U.S. defensive surface-to-air missiles, attested from 1952.
nil (n.): "nothing," 1833, from Latin nil, contraction of nihil, nihilum "nothing, not at all; in vain," from ne- "not" (see un-) + hilum "small thing, trifle," of unknown origin.
Nile: one of the world's oldest surviving place names, from a Semitic root nahal "river." Unnamed in Old Testament, it is always merely "the river" (Hebrew yeor).
nill (v.): Old English nylle, nelle "to be unwilling," from ne "no" (see no) + will (v.). Often paired with will; the construction in nill he, will he, once common, attested from c.1300, surviving principally in willy-nilly, which, however, reverses the usual Middle English word order. Latin expressed a similar idea in nolens volens.
Nilo-: used as a comb. form of Nile.
nim (v.): "to take, to steal" (archaic), Old English niman "to take, accept, receive, grasp, catch" (cf. Old Frisian nima, Middle Dutch nemen, German nehmen, Gothic niman; see nimble). The native word, replaced by Scandinavian-derived take (v.) and out of use from c.1500 except in slang sense of "to steal," which endured into 19c.
nimble (adj.): "agile, light-footed," c.1300, nemel, from Old English næmel "quick to grasp" (attested but once), related to niman "to take," from Proto-Germanic *nemanan (cf. Old Saxon, Old Dutch, Gothic niman, Old Norse nema, Old Frisian nima, German nehmen "to take"), from PIE root *nem- "to divide, distribute, allot," also "to take" (cf. Greek nemein "to deal out," nemesis "just indignation," Latin numerus "number," Lithuanian nuoma "rent, interest," Middle Irish nos "custom, usage"). With excrescent -b- from c.1500 (cf. limb (n.1)). Related: Nimbleness. In 17c., English had nimblechaps "talkative fellow."
nimbly (adv.): mid-14c., from nimble + -ly (adv.).
nimbostratus (n.): 1932 (earlier use from late 19c. refers to different cloud types), from Modern Latin nimbus (see nimbus) + connecting element -o- + stratus (see stratus).
nimbus (n.): 1610s, "bright cloud surrounding a god," from Latin nimbus "cloud," perhaps related to nebula "cloud, mist" (see nebula). Meaning "halo" is first recorded c.1730. Meteorological sense of "a rain cloud" is from 1803.