Online Etymology Dictionary

gnocchi (n.): type of small potato dumplings, 1891, from Italian gnocchi, plural of gnocco, from nocchio "a knot in wood," perhaps from a Germanic source akin to knuckle (n.), gnarled, etc. So called for their shape.
gnome (n.1): "dwarf-like earth-dwelling spirit," 1712, from French gnome (16c.), from Medieval Latin gnomus, used 16c. in a treatise by Paracelsus, who gave the name pigmaei or gnomi to elemental earth beings, possibly from Greek *genomos "earth-dweller" (compare thalassonomos "inhabitant of the sea"). A less-likely suggestion is that Paracelsus based it on the homonym that means "intelligence" (see gnome (n.2)).

Popularized in England in children's literature from early 19c. as a name for red-capped German and Swiss folklore dwarfs. Garden figurines of them were first imported to England late 1860s from Germany; garden-gnome attested from 1933. Gnomes of Zurich for "international financiers" is from 1964.
gnome (n.2): "short, pithy statement of general truth," 1570s, from Greek gnome "judgment, opinion; maxim, the opinion of wise men" (see gnomic).
gnomic (adj.): "full of instructive sayings," 1784, from French gnomique (18c.) and directly from Late Latin gnomicus "concerned with maxims, didactic," from Greek gnomikos, from gnome "a means of knowing, a mark, token; the mind (as the organ of knowing), thought, judgment, intelligence; (one's) mind, will, purpose; a judgment, opinion; maxim, the opinion of wise men," from root of gignoskein "to come to know" (see gnostic (adj.)). Gnomical is attested from 1610s.
gnomish (adj.): "resembling a gnome," 1822, from gnome (n.1) + -ish. Related: Gnomishly; gnomishness.
gnomist (n.): 1865; see gnome (n.2) + -ist.
gnomon (n.): "vertical shaft that tells time by the shadow it casts" (especially the triangular plate on a sundial), 1540s, from Latin gnomon, from Greek gnomon "indicator (of a sundial), carpenter's rule," also, in plural, "the teeth that mark the age of a horse or mule," literally "one that discerns or examines," from gignoskein "to come to know" (see gnostic (adj.)). In geometry from 1560s, from a use in Greek. In early use in English sometimes folk-etymologized as knowman. Related: Gnomonic.
gnosis (n.): "knowledge," especially "special knowledge of spiritual mysteries," 1703, from Greek gnosis "a knowing, knowledge; a judicial inquiry, investigation; a being known," in Christian writers, "higher knowledge of spiritual things," from PIE *gno-ti-, from root *gno- "to know" (see gnostic (adj.)).
Gnostic (n.): 1580s, "believer in a mystical religious doctrine of spiritual knowledge," from Late Latin Gnosticus "a Gnostic," from Late Greek Gnostikos, noun use of adjective gnostikos "knowing, able to discern, good at knowing," from gnostos "known, to be known," from gignoskein "to learn, to come to know" (see gnostic (adj.)). Applied to various early Christian sects that claimed direct personal knowledge beyond the Gospel or the Church hierarchy; they appeared in the first century A.D., flourished in the second, and were stamped out by the 6th.
gnostic (adj.): "relating to knowledge," especially mystical or esoteric knowledge of spiritual things, 1650s, from Greek gnostikos "knowing, good at knowing, able to discern," from gnostos "known, perceived, understood," earlier gnotos, from gignoskein "learn to know, come to know, perceive; discern, distinguish; observe, form a judgment," from PIE *gi-gno-sko-, reduplicated and suffixed form of root *gno- "to know" (see know (v.)).
Gnosticism (n.): 1660s, from Gnostic + -ism.
GNP (n.): abbreviation of gross national product, attested by 1953.
gnu (n.): ox-like South African antelope, 1777, gnoo, from Dutch gnoe, used by German traveler Georg Forster (1754-1794) to render Hottentot i-ngu "wildebeest," from Southern Bushman !nu: (in which ! and : represent clicks).
go (v.): Old English gan "to advance, walk; depart, go away; happen, take place; conquer; observe, practice, exercise," from West Germanic *gaian (source also of Old Saxon, Old Frisian gan, Middle Dutch gaen, Dutch gaan, Old High German gan, German gehen), from PIE *ghe- "to release, let go" (source also of Sanskrit jihite "goes away," Greek kikhano "I reach, meet with"), but there does not seem to be general agreement on a list of cognates.

A defective verb throughout its recorded history; the Old English past tense was eode, a word of uncertain origin but evidently once a different verb (perhaps connected to Gothic iddja); it was replaced 1400s by went, past tense of wenden "to direct one's way" (see wend). In northern England and Scotland, however, eode tended to be replaced by gaed, a construction based on go. In modern English, only be and go take their past tenses from entirely different verbs.

The word in its various forms and combinations takes up 45 columns of close print in the OED. Meaning "cease to exist" is from c. 1200; that of "to appear" (with reference to dress, appearance, etc.) is from late 14c.; that of "to be sold" is from early 15c. Meaning "to be known" (with by) is from 1590s; that of "pass into another condition or state" is from 1580s. From c. 1600 as "to wager," hence also "to stand treat," and to go (someone) better in wagering (1864). Meaning "say" emerged 1960s in teen slang. Colloquial meaning "urinate or defecate" attested by 1926, euphemistic (compare Old English gong "a privy," literally "a going"). To go back on "prove faithless to" is from 1859; to go under in the figurative sense "to fail" is from 1849. To go places "be successful" is by 1934.
go (n.): 1727, "action of going," from use of go (v.) to start a race, etc. Meaning "an incident, an occurrence, affair, piece of business" is from 1796. Meaning "power of going, dash, vigor" is from 1825, colloquial, originally of horses. The sense of "an attempt, a try or turn at doing something" (as in give it a go, have a go at) is from 1825 (earlier it meant "a delivery of the ball in skittles," 1773). Meaning "something that goes, a success" is from 1876. Phrase on the go "in constant motion" is from 1843. Phrase from the word go "from the beginning" is by 1834. The go "what is in fashion" is from 1793. No go "of no use" is from 1825.
go (adj.): "in order," 1951, originally in aerospace jargon, from go (v.).
go down (v.): c. 1300, "droop, descend," from go (v.) + down (adv.). Meaning "decline, fail" is from 1590s. Sense of "to happen" is from 1946, American-English slang. Go down on "perform oral sex on" is from 1916.
go for (v.): 1550s, "be taken or regarded as," also "be in favor of," from go (v.) + for (adv.). Meaning "attack, assail" is from 1880. Go for broke is from 1951, American English colloquial.
go off (v.): 1570s, of firearms, etc., "explode, be discharged;" see go (v.) + off (adv.); meaning "depart" is c. 1600; that of "deteriorate in condition" is from 1690s; that of "reprimand" is from 1941 (originally with at, since c. 2000 more often with on).
go on (v.): 1580s, "advance, proceed," from go (v.) + on (adv.). Meaning "behave, carry on" is from 1777; especially "to talk volubly" (1863). As an expression of derision by 1886.
go out (v.): early 13c., "leave home," from go (v.) + out (adv.). Meaning "become extinct, expire" is from c. 1400.
go over (v.): 1580s, "review point by point;" see go (v.) + over (adv.). Meaning "be successful" is from 1923.
go south (v.): "vanish, abscond," 1920s, American English, probably from mid-19c. notion of disappearing south to Mexico or Texas to escape pursuit or responsibility, reinforced by Native American belief (attested in colonial writing mid-18c.) that the soul journeys south after death.
go through (v.): "to execute, carry to completion" (a plan, etc., often with with), 1560s; see go (v.) + through (adv.). Meaning "to examine" is 1660s; "to endure, suffer, undergo" is by 1712; "to wear out" (of clothes, etc.) by 1959.
go together (v.): 1520s, "accompany," see go (v.) + together (adv.). From 1710 as "agree with, harmonize with;" 1899 as "be courting."
go west (v.): 19c. British idiom for "die, be killed" (popularized during World War I), "probably from thieves' slang, wherein to go west meant to go to Tyburn, hence to be hanged, though the phrase has indubitably been influenced by the setting of the sun in the west" [Partridge]. Compare go south.
go-ahead (adj.): by 1840, "pushing, driving," from verbal phrase go ahead; see go (v.) + ahead (adv.). Go ahead as a command or invitation to proceed is from 1831, American English.
go-between (n.): "one who passes between parties in a negotiation or intrigue," 1590s, from verbal phrase go between in obsolete sense "act as a mediator" (1540s), from go (v.) + between.
go-by (n.): 1640s, "an evasion, a leaving behind by artifice," from verbal phrase; see go (v.) + by (adv.). From 1650s as "a passing without notice, intentional disregard." Compare bygone.
go-cart (n.): also gocart, 1670s, originally "a litter, sedan chair;" also "an infant's walker" (1680s), from go + cart (n.). Later also of hand carts (1759). The modern form go-kart (1959) was coined in reference to a kind of miniature racing car with a frame body and a two-stroke engine.
go-getter (n.): 1910, American English, from go + agent noun from get (v.). Goer, with essentially the same meaning, is attested from late 14c.
go-go (adj.): 1964, "fashionable," from slang adjective go "fashionable" (1962); see go (n.). First appearance of go-go dancer is from 1965.
go-it-alone (adj.): attested by 1953 (in reference to U.S. foreign policy proposals), from an American English verbal phrase attested by 1842 and meaning "do anything without assistance." Go it as colloquial for "to act" (especially in a determined or vigorous way) is from 1825; hence also American English go it blind (1842) in reference to something done without regard for consequences.
go-round (n.): "act of going round," originally especially "a merry-go-round," 1886, from go (v.) + round (adv.). Figurative sense of "argument, bout, fight," etc. is from 1891.
go-to-meeting (adj.): "suitable for use in a church or on Sundays," 1790, especially of clothes but the earliest recorded reference is to music.
Goa: former Portuguese colony in India, from local goe mat "fertile land." Related: Goanese.
goad (n.): Old English gad "point, spearhead, arrowhead, pointed stick used for driving cattle," from Proto-Germanic *gaido "goad, spear" (source also of Lombardic gaida "spear"), from suffixed form of PIE root *ghei- (1) "to propel, prick" (source also of Sanskrit hetih "missile, projectile," himsati "he injures;" Avestan zaena- "weapon;" Greek khaios "shepherd's staff;" Old English gar "spear;" Old Irish gae "spear"). Figurative use "anything that urges or stimulates" is since 16c., probably from the Bible.
goad (v.): 1570s, from goad (n.); earliest use is figurative, "incite, stimulate, instigate." Literal use by 1610s. Related: Goaded; goading.
goal (n.): 1530s, "end point of a race," of uncertain origin. It appears once before this (as gol), in a poem from early 14c. and with an apparent sense of "boundary, limit." Perhaps from Old English *gal "obstacle, barrier," a word implied by gælan "to hinder" and also found in compounds (singal, widgal). That would make it a variant or figurative use of Middle English gale "a way, course." Also compare Old Norse geil "a narrow glen, a passage." Or from Old French gaule "long pole, stake," which is from Germanic. Sports sense of "place where the ball, etc. is put to score" is attested from 1540s. Figurative sense of "object of an effort" is from 1540s.
goal-post (n.): 1834, from goal (n.) + post (n.1). To move the goal posts as a figurative expression for "cheat by changing the objectives after the process has begun" is by 1988.
goalie (n.): 1921, from goal + -ie. Probably a shortening of goal-tender (1889), which tends to be the term used in ice hockey and lacrosse, as opposed to goal-keeper (1650s).
goalless (adj.): 1835, of journeys, etc., "without a fixed destination or purpose," from goal + -less. By 1903 of sports matches where nobody scores. Related: Goallessly; goallessness.
goat (n.): Old English gat "she-goat," from Proto-Germanic *gaito (source also of Old Saxon get, Old Norse geit, Danish gjed, Middle Dutch gheet, Dutch geit, Old High German geiz, German Geiß, Gothic gaits "goat"), from PIE *ghaid-o- "young goat," also forming words for "to play" (source also of Latin hædus "kid").
They are sprightly, capricious, and wanton, and their strong odor (technically called hircine) is proverbial. [Century Dictionary]
The word for "male goat" in Old English was bucca or gatbucca (see buck (n.)) until late 1300s shift to he-goat, she-goat (Nanny goat is 18c., billy goat 19c.). Meaning "licentious man" is attested from 1670s (hence goat-milker, name of a bird formerly believed to suck the milk from goats at night, but also old slang for "a prostitute," also "the female pudendum"). To get (someone's) goat is from 1910, American English, perhaps from French prendre sa chèvre "take one's source of milk," or more likely with notion of "to steal a goat mascot" from a racehorse, warship, fire company, military unit, etc.
... to become separated from your goat is a thing no soldierman is willing to contemplate. ["Letitia, Nursery Corps, U.S.A.," in American Magazine, vol. 64, June 1907]
goatee (n.): "pointed tuft of beard on the chin of a shaven face," 1844 (as goaty; current spelling by 1847), from goaty (adj.). So called from its resemblance to a male goat's chin hairs.
goatherd (n.): "one whose occupation is the care of goats," early 13c. (as a surname), from or replacing Old English gat-hyrde (West Saxon); see goat + herd (n.).
goatish (adj.): "resembling a goat," especially "stinking" or "lustful," 1520s, from goat + -ish. Related: Goatishly; goatishness.
goatskin (n.): late 14c., from goat + skin (n.).
goaty (adj.): "goat-like," c. 1600, from goat + -y (2).
gob (n.1): "a mouthful, lump," late 14c., from gobbet.
gob (n.2): "mouth," 1540s, from Irish gob "mouth," and thus related to the other English noun gob (see gobbet). Gob-stopper "type of large hard candy" is from 1928.