Online Etymology Dictionary

Giles: masc. proper name, from Old French Gilles, from Latin Egidius, Aegidius (name of a famous 7c. Provençal hermit who was a popular saint in the Middle Ages), from Greek aigidion "kid" (see aegis). Often used in English as a typical name of a simple-minded farmer.
gill (n.1): "organ of breathing in fishes," early 14c., of unknown origin, perhaps related to Scandinavian words, such as Old Norse gjölnar which perhaps means "gills," and Old Danish -gæln (in fiske-gæln "fish gill"); said to be ultimately from a PIE *ghel-una- "jaw" (cognate: Greek kheilos "lip"). Related: Gills.
gill (n.2): liquid measure (commonly a half-pint), late 13c., from Old French gille, a wine measure, and from Medieval Latin gillo "earthenware jar," words of uncertain origin, perhaps related to the source of gallon.
Gill: fem. proper name, shortened form of Gillian. Also see Jill. Gill-flirt "giddy young woman" is from 1630s.
Gillian: fem. proper name, from French Juliane, from Late Latin Juliana (a saint's name), fem. of Iulianus, literally "of Julius," the Roman gens name (see Julius).
gillyflower (n.): type of flowering plant, 1550s, folk etymology alteration (by association with unrelated flower) of gilofre "gillyflower" (late 14c.), originally "clove" (c. 1300), from Old French girofle "clove" (12c.), from Latin caryophyllon, from Greek karyophyllon "clove, nut leaf, dried flower bud of clove tree," from karyon "nut" (see karyo-) + phyllon "leaf" (see phyllo-). The flower so named for its scent.
gilt (adj.): "gilded," c. 1400, past participle of Middle English gilden "to gild," from Old English gyldan (see gild (v.)). Also used as a noun with a sense of "gilding" (early 15c.).
gimbal (n.): 1570s, "joints, connecting links," alteration of gemel "twins" (late 14c.), from Old French jumel "a twin" (12c., Modern French jumeau), from Latin gemellus, diminutive of geminus (adj.) "twin, born together" (see geminate). As a type of contrivance for securing free motion in suspension, by 1780. Related: Gimbals. Gemmels (plural) was Middle English for "twins" (late 14c.), also "Gemini," from Old French gemeles; hence also gemel ring, a double finger-ring that may be taken apart; also gimmal.
gimcrack (n.): also jimcrack, "trifle, knick-knack," by c. 1820, earlier "mechanical contrivance" (1630s), originally "showy person" (1610s), of uncertain origin. Perhaps an alteration of Middle English gibecrake, the name of some kind of ornament on wooden furniture (mid-14c.), which is perhaps from Old French giber "to rattle, shake" + some special sense of Middle English crak "sharp noise, crack." In 18c.-19c. gimcrack also could mean "person who has a turn for mechanical contrivances."
gimlet (n.): type of boring tool, mid-14c., gymbelette, from Anglo-French and Old French guimbelet, guibelet (12c., Modern French gibelet), which is probably of Germanic origin, perhaps from Middle Dutch wimmelkijn (with substitute of French diminutive suffix), diminutive of wimmel "auger, drill." Middle English also had wimble in the same sense (mid-13c.), probably from an Old North French form of the same word. As the name of a cocktail made with gin or vodka and lime juice, by 1928, presumably from its "penetrating" effects on the drinker.
gimme (v.): by 1828, representing the colloquial contraction of give me. To have the gimmes "be eagerly greedy" is from 1918; gimme cap attested by 1978. Middle English had yemme, gemme, contractions of yeve me (Middle English form of give me).
TOMMY -- Gimme a cake.
MAMMA -- If what? -- If you please .
TOMMY -- O, let up on that Pinafore business; gimme a cake!
["Puck," July 2, 1878]
gimmick (n.): 1910, American English, perhaps an alteration of gimcrack, or an anagram of magic.
In a hotel at Muscatine, Iowa, the other day I twisted the gimmick attached to the radiator, with the intention of having some heat in my Nova Zemblan booth. ["Domestic Engineering," January 8, 1910]
gimmickry (n.): also gimmickery, by 1950, from gimmick + -ry.
gimmicky (adj.): 1948, from gimmick + -y (2).
gimp (n.1): 1925, "a crippled leg," also "a crippled person" (1929), perhaps by association with limp, or a corruption of gammy (see game (adj.)).
gimp (n.2): also gymp, ornamental material for trimming dresses, furniture, etc., 1660s, probably from French guimpe, Old French guimple "wimple, headdress, veil" (12c.), from Frankish *wimpil- or some other Germanic source (compare Old High German wimpal, and see wimple).
gimpy: 1925 as a noun, "lame person;" 1931 as an adjective, "lame, crippled," hobo slang, from gimp (n.1) + -y (3) and (2).
gin (n.1): type of distilled drinking alcohol, 1714, shortening of geneva, altered (by influence of the name of the Swiss city, with which it has no connection) from Dutch genever "gin," literally "juniper" (because the alcohol was flavored with its berries), from Old French genevre "the plant juniper" (12c.), from Vulgar Latin *jeniperus, from Latin juniperus "juniper" (see juniper). Gin and tonic is attested by 1873; gin-sling by 1790; gin-fizz (with lemon juice and aerated water) is from 1878. Gin-mill, U.S. slang for "low-class tavern or saloon where spirits are drunk" (1872) might be a play on the senses from gin (n.2). British gin-palace "gaudily decorated tavern or saloon where spirits are drunk" is from 1831.

The card game gin rummy first attested 1941 (described in "Life" that year as the latest Hollywood fad); OED lists it with the entries for the liquor, but the sense connection seems obscure other than as a play on rummy.
gin (n.2): "machine for separating cotton from seeds," 1796, American English, used earlier of other machineries, especially of war or torture, from Middle English gin "ingenious device, contrivance" (c. 1200), from Old French gin "machine, device, scheme," shortened form of engin (see engine). The verb in this sense is recorded from 1789. Related: Ginned; ginning. Middle English had ginful "ingenious, crafty; guileful, treacherous" (c. 1300).
gin (v.1): in slang phrase gin up "enliven, make more exciting," 1887 (ginning is from 1825), perhaps a special use of the verb associated with gin (n.2) "engine," but perhaps rather or also from ginger up in the same sense (1849), which is from ginger in sense of "spice, pizzazz;" specifically in reference to the treatment described in the 1811 edition of Grose's slang dictionary under the entry for feague:
... to put ginger up a horse's fundament, and formerly, as it is said, a live eel, to make him lively and carry his tail well; it is said, a forfeit is incurred by any horse-dealer's servant, who shall shew a horse without first feaguing him. Feague is used, figuratively, for encouraging or spiriting one up.
gin (v.2): "to begin," c. 1200, ginnen, shortened form of beginnen (see begin).
ginger (n.): mid-14c., from Old English gingifer, gingiber, from Late Latin gingiber, from Latin zingiberi, from Greek zingiberis, from Prakrit (Middle Indic) singabera, from Sanskrit srngaveram, from srngam "horn" + vera- "body," so called from the shape of its root. But this may be Sanskrit folk etymology, and the word may be from an ancient Dravidian word that also produced the Malayalam name for the spice, inchi-ver, from inchi "root."

The word apparently was readopted in Middle English from Old French gingibre (12c., Modern French gingembre). In reference to coloring, by 1785 of fighting cocks, 1885 of persons (gingery with reference to hair is from 1852). Meaning "spirit, spunk, temper" is from 1843, American English (see gin (v.1)). Ginger-ale is recorded by 1822, the term adopted by manufacturers to distinguish their product from ginger beer (1809), which was sometimes fermented. Ginger-snap as a type of hard cookie flavored with ginger is from 1855, American English.
gingerbread (n.): late 13c., gingerbrar, "preserved ginger," from Old French ginginbrat "ginger preserve," from Medieval Latin gingimbratus "gingered," from gingiber (see ginger). The ending changed by folk etymology to -brede "bread," a formation attested by mid-14c. Meaning "sweet cake spiced with ginger" is from 15c. Figurative use, indicating anything considered showy and insubstantial, is from c. 1600. Sense of "fussy decoration on a house" is first recorded 1757; gingerbread-work (1748) was a sailor's term for carved decoration on a ship. Gingerbread-man as a confection is from 1850; the rhyme ("The Chase of the Gingerbread Man," by Ella M. White) is from 1898.
gingerly (adv.): "extremely cautiously" (of movements, etc.), c. 1600, earlier "elegantly, daintily" (1510s), of unknown origin. Perhaps [OED] from Old French gensor, comparative of gent "dainty, delicate," from Latin gentius "(well)-born" (see gentle). Meaning "extremely cautiously" is from c. 1600.
gingham (n.): cotton fabric woven of plain dyed yarns, 1610s, from Dutch gingang, a traders' rendering of a Malay word said to be ginggang, meaning "striped" [OED], or else "perishable, fading" [Century Dictionary], used as a noun with the sense of "striped cotton." Also from the same source are French guingan (18c.), Spanish guinga, Italian gingano, German gingang.
gingival (adj.): 1660s, from Latin gingivae "the gums" (of unknown origin) + -al (1).
gingivitis (n.): 1874, from Latin gingivae "the gums" (of unknown origin) + -itis "inflammation."
gink (n.): "a fellow, man," American English slang, 1910, of unknown origin.
ginkgo (n.): 1773, from Japanese ginkyo, from Chinese yin-hing, from yin "silver" + hing "apricot" (Sino-Japanese kyo). Introduced to New World 1784 by William Hamilton in his garden near Philadelphia; also formerly known as the maidenhair-tree, from resemblance of the tree's leaves to those of the fern.
Ginnie Mae: 1970, fleshed out in the form of a fem. proper name, from GNMA, acronym of Government National Mortgage Association.
ginormous (adj.): by 1948, perhaps 1942, apparently originally a World War II military colloquialism, from a merger of gigantic + enormous.
ginseng (n.): type of plant whose root is highly valued as a tonic and stimulant in Chinese herbology, 1650s, from Chinese jen-shen. First element means "man," but the meaning of the second is obscure.
Gioconda: La Gioconda, name of the da Vinci painting also known as the Mona Lisa (q.v.), from Italian Gioconda, fem. of Giocondo, the surname of her husband (Francesco del Giocondo); the name is from Late Latin jocundus, literally "pleasing, pleasant" (see jocund). Hence the French name of the painting, La Joconde.
gip: attested from 1840 as an abbreviation of gipsy (also see gypsy). Also see gyp. Related: Gipped; gipping.
Gipsy: alternative spelling of Gypsy. OED gives it precedence, and it is the main form for the word's entry in Century Dictionary, but Fowler writes that "the first y is highly significant, reminding us that Gypsy means Egyptian ...."
giraffe (n.): long-necked ruminant animal of Africa, 1590s, giraffa, from Italian giraffa, from Arabic zarafa, probably from an African language. Earlier Middle English spellings varied wildly, depending on the foreign source, and included jarraf, ziraph, and gerfauntz, some apparently directly from Arabic, the last reflecting some confusion with olifaunt "elephant."
In Arabye, þei ben clept Gerfauntz; þat is a best pomelee or spotted .. but a lityll more high þan is a stede, But he hath the necke a xxti cubytes long. [Mandeville's Travels, c. 1425]
The modern form of the English word is attested by c. 1600 and is via French girafe (13c.). Replaced earlier camelopard, a compound of camel (for the long neck) and pard (n.1) "leopard" (for the spots).
girandole (n.): 1630s, a type of fireworks; 1769 as a branched holder for candles; 1825 as a type of earring or pendant, from French girandole, from Italian girandola, diminutive of giranda "a revolving jet," from Latin gyrandus, gerundive of gyrare "to turn round in a circle, revolve" (see gyration). Also in English in the Italian form.
girasole (n.): 1580s, "a sunflower," also the name of a type of opal, from Italian girasole "sunflower," literally "turning toward the sun," from girare "to rotate" (see gyre (n.)) + sole (see Sol).
gird (v.): Old English gyrdan "put a belt or girdle around; encircle; bind with flexible material; invest with attributes," from Proto-Germanic *gurdjan (source also of Old Norse gyrða, Old Saxon gurdian, Old Frisian gerda, Dutch gorden, Old High German gurtan, German gürten), from PIE *ghr-dh-, suffixed form of root *gher- (1) "to grasp" (see yard (n.1)). Related: Girded; girding.
Throughout its whole history the English word is chiefly employed in rhetorical language, in many instances with more or less direct allusion to biblical passages. [OED]
As in to gird oneself "tighten the belt and tuck up loose garments to free the body in preparation for a task or journey."
girder (n.): "main supporting wooden beam that carries flooring," 1610s, agent noun from gird, on notion of something that "holds up" something else. Used of iron bridge supports from 1853.
girdle (n.): Old English gyrdel "belt, sash, cord drawn about the waist and fastened," worn by both men and women, common Germanic (cognates: Old Norse gyrðill, Swedish gördel, Old Frisian gerdel, Dutch gordel, Old High German gurtil, German Gürtel "belt"), from the same source as Old English gyrdan "to gird" (see gird) with instrumental suffix -el (1). Modern euphemistic sense of "elastic corset not extending above the waist" first recorded 1925. Originally a belt to secure the clothes, also for carrying a purse, a weapon, keys, etc.
girdle (v.): "encircle with a girdle," 1580s, from girdle (n.). Meaning "to cut off a belt of bark around a trunk to kill a tree" is from 1660s, especially in North America. Related: Girdled; girdling.
girl (n.): c. 1300, gyrle "child, young person" (of either sex but most frequently of females), of unknown origin. One guess [OED] leans toward an unrecorded Old English *gyrele, from Proto-Germanic *gurwilon-, diminutive of *gurwjoz (apparently also represented by Low German gære "boy, girl," Norwegian dialectal gorre, Swedish dialectal gurre "small child," though the exact relationship, if any, between all these is obscure), from PIE *ghwrgh-, also found in Greek parthenos "virgin." But this involves some objectionable philology. Liberman (2008) writes:
Girl does not go back to any Old English or Old Germanic form. It is part of a large group of Germanic words whose root begins with a g or k and ends in r. The final consonant in girl is a diminutive suffix. The g-r words denote young animals, children, and all kinds of creatures considered immature, worthless, or past their prime.
Another candidate is Old English gierela "garment" (for possible sense evolution in this theory, compare brat). A former folk-etymology derivation from Latin garrulus "chattering, talkative" is now discarded. Like boy, lass, lad it is of more or less obscure origin. "Probably most of them arose as jocular transferred uses of words that had originally different meaning" [OED]. Specific meaning of "female child" is late 14c. Applied to "any young unmarried woman" since mid-15c. Meaning "sweetheart" is from 1640s. Old girl in reference to a woman of any age is recorded from 1826. Girl next door as a type of unflashy attractiveness is recorded by 1953.
Doris [Day] was a big vocalist even before she hit the movies in 1948. There, as the latest movie colony "girl next door," sunny-faced Doris soon became a leading movie attraction as well as the world's top female recording star. "She's the girl next door, all right," said one Hollywood admirer. "Next door to the bank." ["Life" magazine, Dec. 22, 1958]
Girl Friday "resourceful young woman assistant" is from 1940, a reference to "Robinson Crusoe." Girl Scout is from 1909. For the usual Old English word, see maiden.
girlfriend (n.): also girl-friend, by 1859 as "a woman's female friend in youth," from girl + friend (n.). As a man's sweetheart, by 1922. She-friend was used 17c. in the same set of senses, of the mistress of a man and of a woman who is a close friend of another.
girlhood (n.): 1785, from girl + -hood.
girlie (adj.): "meant to titillate men, featuring attractive women scantily clad or nude," 1942, from girl + -y (2).
girlish (adj.): 1560s, "like or befitting a girl," from girl + -ish. Related: Girlishly; girlishness.
girly (adj.): "girl-like," 1866, from girl + -y (2). Reduplicated form girly-girly (adj.) is recorded from 1883; as a noun from 1882.
girly (n.): girlie, "little girl," 1860, from girl + -y (3). Another diminutive was girleen (1836) with an Irish ending.
Girondist (n.): 1795, member of the moderate republican party of France, 1791-93, from Gironde, name of a department in southwestern France; the faction so called because its leaders were deputies elected from there.