nerd (n.) Look up nerd at Dictionary.com
1951, U.S. student slang, probably an alteration of 1940s slang nert "stupid or crazy person," itself an alteration of nut. The word turns up in a Dr. Seuss book from 1950 ("If I Ran the Zoo"), which may have contributed to its rise.
nerdy (adj.) Look up nerdy at Dictionary.com
1978, from nerd + -y (2). Related: Nerdiness.
Nereid Look up Nereid at Dictionary.com
"sea-nymph," 1510s, from Greek Nereis (genitive Nereidos), daughter of the ancient sea-god Nereus, whose name is related to naros "flowing, liquid, I flow" (see naiad).
nerf Look up nerf at Dictionary.com
1955, in nerf bars, hot-rodder slang for "custom bumpers;" from slang verb in auto racing (1953) meaning "to nudge something with a bumper in passing and knock it off course;" ultimate origin and signification unknown.

As a trademark name for toys made of foam-like material for indoor play, introduced 1970 (Nerf ball). By 1995 this had yielded a verbal sense of "to make less effective" (as a Nerf basketball is softer and lighter than the real thing).
neritic (adj.) Look up neritic at Dictionary.com
1891, from German neritisch (Haeckel, 1890), perhaps from Nerita, a genus of molluscs.
nertz (interj.) Look up nertz at Dictionary.com
1932, originally American English college slang, colloquial or euphemistic pronunciation of nuts as a slang retort of defiance or dismissal (1931).
nerve (n.) Look up nerve at Dictionary.com
late 14c., nerf "sinew, tendon," from Old French nerf and directly from Medieval Latin nervus "nerve," from Latin nervus "sinew, tendon; cord, bowstring," metathesis of pre-Latin *neuros, from PIE *(s)neu- "tendon, sinew" (cognates: Sanskrit snavan- "band, sinew," Armenian neard "sinew," Greek neuron "sinew, tendon," in Galen "nerve"). Sense of "fibers that convey impulses between the brain and the body" is from c.1600.

Secondary senses developed from meaning "strength, vigor, energy" (c.1600), from the "sinew" sense. Hence figurative sense of "feeling, courage," first attested c.1600; that of "courage, boldness" is from 1809; bad sense "impudence, cheek" is from 1887. Latin nervus also had a figurative sense of "vigor, force, power, strength," as did Greek neuron. From the neurological sense come Nerves "condition of nervousness," attested from 1792; to get on someone's nerves, from 1895. War of nerves "psychological warfare" is from 1915.
nerve (v.) Look up nerve at Dictionary.com
c.1500, "to ornament with threads;" see nerve (n.). Meaning "to give strength or vigor" is from 1749. Related: Nerved; nerving.
nerve-racking (adj.) Look up nerve-racking at Dictionary.com
also nerveracking, 1812, from nerve + present participle of verbal sense of rack (n.1).
nerve-wracking (adj.) Look up nerve-wracking at Dictionary.com
also nervewracking, 1867, from nerve + present participle of wrack (v.).
nervous (adj.) Look up nervous at Dictionary.com
c.1400, "affecting the sinews," from Latin nervosus "sinewy, vigorous," from nervus "sinew, nerve" (see nerve). Meaning "of or belonging to the nerves" in the modern sense is from 1660s. Meaning "suffering disorder of the nervous system" is from 1734; illogical sense "restless, agitated, lacking nerve" is 1740. Widespread popular use as a euphemism for mental forced the medical community to coin neurological to replace it in the older sense. Nervous wreck first attested 1862. Related: Nervously; nervousness.
nervy (adj.) Look up nervy at Dictionary.com
"full of courage," 1870, from nerve + -y (2). Sense of "excitable" is from 1891.
nescience (n.) Look up nescience at Dictionary.com
"ignorance," 1610s, from Late Latin nescientia, from nesciens (see nescient).
nescient (adj.) Look up nescient at Dictionary.com
1620s, from Latin nescientem (nominative nesciens) "ignorant, unaware," present participle of nescire "not to know, to be ignorant," from ne "not" + scire "to know" (see science).
nesh (adj.) Look up nesh at Dictionary.com
"tender, delicate, weak," now a Northern England dialect word, from Old English hnesce "soft in texture" (cognate with early modern Dutch nesch, Gothic hnasqus), of unknown origin.
ness (n.) Look up ness at Dictionary.com
obsolete except in place names, Old English næs "a promontory," related to nasu "nose" (see nose (n.)). Cognate with Old Norse nes, Danish næs, Swedish näs, Middle Dutch nesse.
Nessie Look up Nessie at Dictionary.com
colloquial name of the "Loch Ness monster," 1945. The loch is named for the river Ness, probably from an Old Celtic word meaning "roaring one."
nest (n.) Look up nest at Dictionary.com
Old English nest "bird's nest, snug retreat," also "young bird, brood," from Proto-Germanic *nistaz (cognates: Middle Low German, Middle Dutch nest, German Nest), from PIE *nizdo- (cognates: Sanskrit nidah "resting place, nest," Latin nidus "nest," Old Church Slavonic gnezdo, Old Irish net, Welsh nyth, Breton nez "nest"), probably from *ni "down" + *sed- (1) "to sit" (see sedentary).

Used since Middle English in reference to various accumulations of things (such as a nest of drawers, early 18c.). Nest egg "retirement savings" is from 1700, originally "a real or artificial egg left in a nest to induce the hen to go on laying there" (c.1600).
nest (v.) Look up nest at Dictionary.com
Old English nistan "to build nests," from Proto-Germanic *nistijanan, from the source of nest (n.). The modern verb is perhaps a new formation in Middle English from the noun. Related: Nested; nesting.
nesting (adj.) Look up nesting at Dictionary.com
1650s, "making or using a nest," past participle adjective from nest (v.). Of objects, "fitted into one another," from 1934.
nestle (v.) Look up nestle at Dictionary.com
Old English nestlian "build a nest," from nest (see nest (n.)). Figurative sense of "settle (oneself) comfortably, snuggle" is first recorded 1540s. Related: Nestled; nestling.
nestling (n.) Look up nestling at Dictionary.com
late 14c., "bird too young to leave the nest," from nest (n.) + diminutive suffix -ling.
Nestor Look up Nestor at Dictionary.com
name for "old king renowned for wise counsel," 1580s, from Greek, name of the aged and wise hero in the "Iliad," king of Pylus, who outlived three generations. Klein says the name is literally "one who blesses," and is related to nostimos "blessed;" Watkins connects it with the root of the first element in nostalgia.
Nestorian (n.) Look up Nestorian at Dictionary.com
in Church history (mid-15c.), a follower of Nestorius (Latinized form of Nestor), 5c. patriarch of Constantinople, whose doctrine attributed distinct divine and human persons to Christ and was condemned as heresy. As an adjective from 1560s. Related: Nestorianism.
net (n.) Look up net at Dictionary.com
Old English net "netting, network, spider web, mesh used for capturing," also figuratively, "moral or mental snare or trap," from Proto-Germanic *natjan (cognates: Old Saxon net, Old Norse, Dutch net, Swedish nät, Old High German nezzi, German Netz, Gothic nati "net"), originally "something knotted," from PIE *ned- "to twist, knot" (cognates: Sanskrit nahyati "binds, ties," Latin nodus "knot," Old Irish nascim "I bind, oblige").
net (adj.) Look up net at Dictionary.com
"remaining after deductions," 1510s, from earlier sense of "trim, elegant, clean, neat" (c.1300), from Old French net "clean, pure," from Latin nitere "to shine, look bright, glitter" (see neat). Meaning influenced by Italian netto "remaining after deductions." As a noun, 1910.
net (v.2) Look up net at Dictionary.com
"to gain as a net sum," 1758, from net (adj.). Related: Netted; netting.
net (v.1) Look up net at Dictionary.com
"to capture in a net," early 15c., from net (n.). Related: Netted; netting.
nether (adj.) Look up nether at Dictionary.com
Old English niþera, neoþera "down, downwards, below, beneath," from Proto-Germanic *nitheraz (cognates: Old Saxon nithar, Old Norse niðr, Old Frisian nither, Dutch neder, German nieder), from comparative of PIE *ni- "down, below" (cognates: Sanskrit ni "down," nitaram "downward," Greek neiothen "from below," Old Church Slavonic nizŭ "low, down"). Has been replaced in most senses by lower (adj.).
Netherlands Look up Netherlands at Dictionary.com
from Dutch Nederland, literally "lower land" (see nether); said to have been used by the Austrians (who ruled much of the southern part of the Low Countries from 1713 to 1795), by way of contrast to the mountains they knew, but the name is older than this. The Netherlands formerly included Flanders and thus were equivalent geographically and etymologically to the Low Countries. Related: Netherlander; Netherlandish (c.1600).
netherworld (n.) Look up netherworld at Dictionary.com
also nether-world, 1630s, "place beneath the earth," from nether + world.
netiquette (n.) Look up netiquette at Dictionary.com
1993, coined punningly from net, short for Internet + etiquette.
netizen (n.) Look up netizen at Dictionary.com
1995, from net, short for Internet + citizen.
nettle (n.) Look up nettle at Dictionary.com
stinging plant, Old English netele, from Proto-Germanic *natilon (cognates: Old Saxon netila, Middle Dutch netele, Dutch netel, German Nessel, M.Da. nædlæ "nettle"), diminutive of *naton, perhaps from PIE root *ned- "to twist, knot" (see net (n.)). "[N]ettles or plants of closely related genera such as hemp were used as a source of fiber" [Watkins].
nettle (v.) Look up nettle at Dictionary.com
c.1400, "to beat with nettles," from nettle (n.). Figurative sense of "irritate, provoke" is from 1560s. Related: Nettled; nettling.
Nettled. Teized, provoked, out of temper. He or she has pissed on a nettle; said of one who is pevish or out of temper. [Grose, "Dictionary of the Vulgar Tongue," 1785]
nettled (adj.) Look up nettled at Dictionary.com
"vexed, irritated," c.1400, figurative adjectival use of past participle of nettle (v.).
nettlesome (adj.) Look up nettlesome at Dictionary.com
1766, from nettle (n.) + -some (1).
network (v.) Look up network at Dictionary.com
1887, "to cover with a network," from network (n.). From 1940 as "to broadcast over a (radio) network;" 1972 in reference to computers; 1980s in reference to persons. Related: Networked; networking.
network (n.) Look up network at Dictionary.com
"net-like arrangement of threads, wires, etc.," 1550s, from net (n.) + work (n.). Extended sense of "any complex, interlocking system" is from 1839 (originally in reference to transport by rivers, canals, and railways). Meaning "broadcasting system of multiple transmitters" is from 1914; sense of "interconnected group of people" is from 1947.
Neufchatel Look up Neufchatel at Dictionary.com
type of soft, white cheese, 1833, from Neufchâtel, small town in Normandy where it first was made.
neural (adj.) Look up neural at Dictionary.com
"pertaining to a nerve or nerves," 1830, from Greek neuron "nerve" (see neuro-) + adjectival suffix -al (1). Related: Neurally.
neuralgia (n.) Look up neuralgia at Dictionary.com
1807, from Greek neuron "nerve" (see neuro-) + -algia. Probably formed on model of French névralgie (1801). Related: Neuralgic.
neurasthenia (n.) Look up neurasthenia at Dictionary.com
"nervous exhaustion," 1854, medical Latin, from neur- (form of neuro- before a vowel) + asthenia "weakness" (see asthenia). Related: Neurasthenic.
neuritis (n.) Look up neuritis at Dictionary.com
"inflammation of a nerve or nerves," 1825, from Greek neuron "nerve" (see neuro-) + -itis. Related: Neuritic.
neuro- Look up neuro- at Dictionary.com
before vowels neur-, word-forming element meaning "pertaining to a nerve or nerves or the nervous system," from Greek neuro-, comb. form of neuron "nerve," originally "sinew, tendon, cord, bowstring," also "strength, vigor," from PIE *(s)neu- "tendon, sinew" (see nerve).
neuroglia (n.) Look up neuroglia at Dictionary.com
1867, medical Latin, coined 1853 by German pathologist Ludwig Karl Virchow (1821-1902) from neuro- + Late Greek glia "glue," frim PIE *glei- "to stick together" (see clay).
neurologist (n.) Look up neurologist at Dictionary.com
1801, from neurology + -ist.
neurology (n.) Look up neurology at Dictionary.com
"scientific study of the nervous system," 1680s, from Modern Latin neurologia, from Modern Greek neurologia (1660s), from neuro- (see neuro-) + -logia "study" (see -logy). Related: Neurological.
neuron (n.) Look up neuron at Dictionary.com
"a nerve cell with appendages," 1891, from German Neuron, from Greek neuron (see neuro-). Used earlier (1884) for "the spinal cord and brain."
neuropathy (n.) Look up neuropathy at Dictionary.com
1827, from neuro- + -pathy. Related: Neuropath; neuropathic; neuropathist.