Online Etymology Dictionary

-y (3): suffix in pet proper names (e.g. Johnny, Kitty), first recorded in Scottish, c.1400; became frequent in English 15c.-16c. Extension to surnames seems to date from c.1940. Use with common nouns seems to have begun in Scottish with laddie (1546) and become popular in English due to Burns' poems, but the same formation appears to be represented much earlier in baby and puppy.
-y (1): noun suffix, in army, city, country, etc., from Old French -e, Latin -atus, -atum, pp. suffix of verbs of the first conjugation. In victory, history, etc. it represents Latin -ia, Greek -ia.
-y (2): adjective suffix, "full of or characterized by," from Old English -ig, from Proto-Germanic *-iga (cf. German -ig), cognate with Greek -ikos, Latin -icus.
-yer: agent noun suffix, variant of -ier used after a vowel or -w-.
-yl: chemical suffix used in forming names of radicals, from French -yle, from Greek hyle "wood," also "building stuff, raw material" (from which something is made).
It was introduced into chemical nomenclature by Liebig and Wohler when, in 1832, they used the term benzoyle for the radical which appeared to be the "essential material" of benzoic acid and related compounds. [Flood]
Y: a late-developing letter in English. Called ipsilon in German, upsilon in Greek, the English name is of obscure origin. The sound at the beginning of yard, yes, yield, etc. is from Old English words with initial g- as in got and y- as in yet, which were considered the same sound and often transcribed as a character that looks something like 3 (but with a flat top and lower on the line of text), known as yogh. The system was altered by French scribes, who brought over the continental use of -g- and from the early 1200s used -y- and sometimes -gh- to replace 3. There's a good, in-depth discussion of yogh here. As short for YMCA, YWCA, YMHA first recorded 1915.
y'all: by 1879, U.S. dialect abbreviation of you all (see you).
Children learn from the slaves some odd phrases ... as ... will you all do this? for, will one of you do this? ["Arthur Singleton" (Henry C. Knight), "Letters from the South and West," 1824]
y-: perfective prefix, in y-clept, etc.; a deliberate archaism, introduced by Spenser and his imitators, representing an authentic Middle English prefix, from Old English ge-, originally meaning "with, together" but later a completive or perfective element, from Proto-Germanic *ga-. It is still living in German and Dutch ge-, and survives, disguised, in some English words (e.g. alike, aware, handiwork).
yacht (n.): 1550s, yeaghe "a light, fast-sailing ship," probably from Norwegian jaght, from Middle Low German jacht, shortened form of jachtschip "fast pirate ship," literally "ship for chasing," from jacht "chase," from jagen "to chase, hunt," from Old High German jagon, from Proto-Germanic *jagojanan.
yack (v.): "to talk, to chatter," slang, 1950, probably echoic (cf. Australian slang yacker "talk, conversation," 1882). Yackety is recorded from 1953.
yadda-yadda: "and so on," 1990s, of echoic origin (cf. yatata "talk idly, chatter," 1940s; and yatter "to talk incessantly or idly," 1825).
yah: exclamation of defiance or dismissal, from 1812.
yahoo (n.): "a brute in human form," 1726, from the race of brutish human creatures in Swift's "Gulliver's Travels." The internet search engine so called from 1994.
Yahtzee (n.): dice game, 1957, proprietary (E.S. Lowe Co., N.Y.), apparently based on yacht.
Yahweh: 1869, hypothetical reconstruction of the tetragrammaton YHWH (see Jehovah), based on the assumption that the tetragrammaton is the imperfective of Hebrew verb hawah, earlier form of hayah "was," in the sense of "the one who is, the existing."
yak (n.): "wild ox of central Asia," 1795, from Tibetan g-yag "male yak."
yak (v.): "laugh," 1938; "talk idly," 1950; echoic, perhaps of Yiddish origin.
yakuza (n.): traditional Japanese organized crime cartel, literally "eight-nine-three" (ya, ku, sa) the losing hand in the traditional baccarat-like Japanese card game Oicho-Kabu. The notion may be "good for nothing," or "bad luck" (such as that suffered by someone who runs afoul of them), or it may be a reference to the fact that a player who draws this hand requires great skill to win.
Yale: 1854, kind of lock invented by U.S. mechanic Linus Yale Jr. (1821-1868). The surname is Welsh, from ial, and means "dweller at the fertile upland." Yale University (Connecticut, U.S.) founded 1701 as Collegiate School, renamed 1718 in honor of a gift from British merchant-philanthropist Elihu Yale (1649-1721).
yam (n.): 1580s, from Portuguese inhame or Spanish igname, from a West African language (cf. Fulani nyami "to eat;" Twi anyinam "species of yam"); the word in American and Jamaican English probably is directly from West African sources.
yammer (v.): late 15c., "to lament," probably from Middle Dutch jammeren and cognate Middle English yeoumeren, "to mourn, complain," from Old English geomrian "to lament," from geomor "sorrowful," probably of imitative origin. Meaning "to make loud, annoying noise" is attested from 1510s. Related: Yammered; yammering.
yang: 1670s, from Mandarin yang "male, daylight, solar."
yank (v.): 1822, Scottish, of unknown origin. Related: Yanked; yanking. The noun is 1818 in sense of "sudden blow, cuff."
Yankee: 1683, a name applied disparagingly by Dutch settlers in New Amsterdam (New York) to English colonists in neighboring Connecticut. It may be from Dutch Janke, literally "Little John," diminutive of common personal name Jan; or it may be from Jan Kes familiar form of "John Cornelius," or perhaps an alteration of Jan Kees, dialectal variant of Jan Kaas, literally "John Cheese," the generic nickname the Flemings used for Dutchmen.

It originally seems to have been applied insultingly to the Dutch, especially freebooters, before they turned around and slapped it on the English. A less-likely theory is that it represents some southern New England Algonquian language mangling of English. In English a term of contempt (1750s) before its use as a general term for "native of New England" (1765); during the American Revolution it became a disparaging British word for all American native or inhabitants. Shortened form Yank in reference to "an American" first recorded 1778.
Yankee Doodle: popular tune of the American Revolution, apparently written c.1755 by British Army surgeon Dr. Richard Schuckburgh while campaigning with Amherst's force in upper New York during the French and Indian War. The original verses mocked the colonial troops serving alongside the regulars, and the Doodle element just may have been, or hinted at, the 18c. slang term for "penis." The song naturally was popular with British troops in the colonies, but after the colonials began to win skirmishes with them in 1775, they took the tune as a patriotic prize and re-worked the lyrics. The current version seems to have been written in 1776 by Edward Bangs, a Harvard sophomore who also was a Minuteman.
yap (v.): c.1600, probably of imitative origin. Originally in reference to dog sounds; meaning "to talk idle chatter" is first recorded 1886. Related: Yapped; yapping.
yappy (adj.): 1909, from yap + -y (2).
yar: growling sound, imitative, attested from c.1300.
yard (n.1): "ground around a house," Old English geard "enclosure, garden, court, house, yard," from Proto-Germanic *garda (cf. Old Norse garðr "enclosure, garden, yard;" Old Frisian garda, Dutch gaard, Old High German garto, German Garten "garden;" Gothic gards "house," garda "stall"), from PIE *gharto-, from root *gher- "to grasp, enclose" (cf. Old English gyrdan "to gird," Sanskrit ghra- "house," Albanian garth "hedge," Latin hortus "garden," Phrygian -gordum "town," Greek khortos "pasture," Old Irish gort "field," Breton garz "enclosure, garden," and second element in Latin cohors "enclosure, yard, company of soldiers, multitude").

Lithuanian gardas "pen, enclosure," Old Church Slavonic gradu "town, city," and Russian gorod, -grad "town, city" belong to this group, but linguists dispute whether they are independent developments or borrowings from Germanic. Yard sale is attested by 1976. Middle English yerd "yard-land" (mid-15c.) was a measure of about 30 acres.
yard (n.2): measure of length, Old English gerd (Mercian), gierd (West Saxon) "rod, stick, measure of length," from West Germanic *gazdijo, from Proto-Germanic *gazdaz "stick, rod" (cf. Old Saxon gerda, Old Frisian ierde, Dutch gard "rod;" Old High German garta, German gerte "switch, twig," Old Norse gaddr "spike, sting, nail"), from PIE *gherdh- "staff, pole" (cf. Latin hasta "shaft, staff"). The nautical yardarm retains the original sense of "stick."

Originally in Anglo-Saxon times a land measure of roughly 5 meters (a length later called rod, pole, or perch). Modern measure of "three feet" is attested from late 14c. (earlier rough equivalent was the ell of 45 inches, and the verge). In Middle English, the word also was a euphemism for "penis" (cf. "Love's Labour's Lost," V.ii.676). Slang meaning "one hundred dollars" first attested 1926, American English.
yardarm (n.): also yard-arm, 1550s, from yard (n.2) + arm (n.1). In 19c. British naval custom, it was permissible to begin drinking when the sun was over the yard-arm.
yardbird (n.): "convict," 1956, from yard (n.1) + bird (n.1), from the notion of prison yards; earlier it meant "basic trainee" (World War II armed forces slang).
yardstick (n.): 1816, from yard (n.2) + stick (n.).
yare (adj.): "ready, prepared," Old English gearo "ready," related to gearwe "clothing, dress" (see gear (n.)). Cf. Dutch gaar "done, dressed;" Old High German garo "ready, prepared, complete."
yarmulke (n.): 1903, from Yiddish yarmulke, from Polish jarmułka, originally "a skullcap worn by priests," perhaps ultimately from Medieval Latin almutia "cowl, hood."
yarn (n.): Old English gearn "spun fiber," from Proto-Germanic *garnan (cf. Old Norse, Old High German, German garn, Middle Dutch gaern, Dutch garen "yarn"), from PIE root *ghere- "intestine, gut, entrail" (cf. Old Norse gorn "gut," Sanskrit hira "vein; entrails," Latin hernia "rupture," Greek khorde "intestine, gut-string," Lithuanian zarna "gut"). The phrase to spin a yarn "to tell a story" is first attested 1812, from a sailors' expression, on notion of telling stories while engaged in sedentary work such as yarn-twisting.
yarrow (n.): plant, also known as milfoil, Old English gearwe, from Proto-Germanic *garwo (cf. Middle Dutch garwe, Old High German garawa, German Garbe), perhaps from a source akin to the root of yellow.
yaw (v.): "to fall away from the line of a course," 1540s, from Old Norse jaga, Old Danish jæge "to drive, chase," from Middle Low German jagen (see yacht).
yawl (n.): type of ship's boat, 1660s, apparently from Middle Low German jolle or Dutch jol "a Juteland boat," of unknown origin. Also borrowed into French (yole), Italian (jolo), Russian (yal).
yawn (v.): c.1300, yenen, yonen, from Old English ginian, gionian "open the mouth wide, gape," from Proto-Germanic *gin- (cf. Old Norse gina "to yawn," Dutch geeuwen, Old High German ginen, German gähnen "to yawn"), from PIE *ghai- "to yawn, gape" (cf. Old Church Slavonic zijajo "to gape," Lithuanian zioju, Czech zivati "to yawn," Greek khainein, Latin hiare "to yawn, gape," Sanskrit vijihite "to gape, be ajar"). Related: Yawned; yawning.
yawn (n.): "act of yawning," 1690s, from yawn (v.). Meaning "boring thing" is attested from 1889.
yawner (n.): 1680s, agent noun from yawn (v.). Meaning "boring thing" is 1942, American English colloquial (yawn in this sense is attested from 1889).
yawp (v.): c.1300, yolpen, probably echoic variant of yelpen (see yelp). Related: Yawped; yawping. The noun, in reference to speech, is recorded from 1835, now used chiefly with conscious echo of Whitman.
yaws (n.): 1670s, from Carib yaya, the native name for the disease.
yay: "this," as in yay big "this big," 1950s, perhaps from yea "yes" in its sense of "even, truly, verily." "a sort of demonstrative adverb used with adjectives of size, height, extent, etc., and often accompanied by a hand gesture indicating size" [DAS].
yclept: Old English gicliopad; see y-.
ye (pron.): Old English ge, nominative plural of 2nd person pronoun þu (see thou); cognate with Old Frisian ji, Old Saxon gi, Middle Dutch ghi, Dutch gij. Cognate with Lithuanian jus, Sanskrit yuyam, Avestan yuzem, Greek hymeis.

Altered, by influence of we, from an earlier form that was similar to Gothic jus "you (plural)" (see you). The -r- in Old Norse er, German ihr probably is likewise from influence of the 1st person plural pronouns (Old Norse ver, German wir).
ye (article): old or quaintly archaic way of writing the, in which the -y- is a 16c. graphic alteration of þ, an Old English character (generally called "thorn," originally a Germanic rune; see th-) that represented the "hard" -th- sound at the beginning of the. Early printers, whose types were founded on the continent, did not have a þ, so they substituted y as the letter that looked most like it. But in such usages it was not pronounced "y." Ye for the (and yt for that) continued in manuscripts through 18c. Revived 19c. as a deliberate antiquarianism; the Ye Olde _____ construction was being mocked by 1896.
yea: Old English gea (West Saxon), ge (Anglian) "so, yes," from Proto-Germanic *ja-, *jai-, a word of affirmation (cf. German, Danish, Norwegian, Swedish ja), from PIE *yam-, from pronomial stem *i- (see yon).
yeah: American English, colloquial, by 1863, from drawling pronunciation of yes.