Online Etymology Dictionary

well-spoken (adj.): mid-15c., from well (adv.) + -spoken.
well-wisher (n.): 1580s, from well (adv.) + agent noun from wish (v.). Well-wishing is recorded from 1560s.
wellaway: mid-13c., alteration (by influence of Scandinavian forms) of Old English wa la wa, literally "woe, lo, woe!" from wa "woe" (see woe).
Wellington (n.): boot so called from 1817, for Arthur, 1st Duke of Wellington (1769-1852), who also in his lifetime had a style of coat, hat, and trousers named for him as well as a variety of apple and pine tree.
wellness (n.): 1650s, from well (adv.) + -ness.
wellspring (n.): Old English welspryng "living spring, fountainhead," literal and figurative; see well (n.) + spring (n.2).
Welsh (adj.): Old English Wielisc, Wylisc (West Saxon), Welisc, Wælisc (Anglian and Kentish) "foreign; British (not Anglo-Saxon), Welsh; not free, servile," from Wealh, Walh "Celt, Briton, Welshman, non-Germanic foreigner;" in Tolkien's definition, "common Gmc. name for a man of what we should call Celtic speech," but also applied in Germanic languages to speakers of Latin, hence Old High German Walh, Walah "Celt, Roman, Gaulish," and Old Norse Val-land "France," Valir "Gauls, non-Germanic inhabitants of France" (Danish vælsk "Italian, French, southern"); from Proto-Germanic *Walkhiskaz, from a Celtic tribal name represented by Latin Volcæ (Caesar) "ancient Celtic tribe in southern Gaul."

As a noun, "the Britons," also "the Welsh language," both from Old English. The word survives in Wales, Cornwall, Walloon, walnut, and in surnames Walsh and Wallace. Borrowed in Old Church Slavonic as vlachu, and applied to the Rumanians, hence Wallachia. Among the English, Welsh was used disparagingly of inferior or substitute things (such as Welsh cricket "louse" (1590s); Welsh comb "thumb and four fingers" (1796), and compare welch (v.)). Welsh rabbit is from 1725, also perverted by folk-etymology as Welsh rarebit (1785).
Welshman (n.): Old English Wilisc mon; see Welsh + man (n.).
welt (n.): early 15c., a shoemaker's term, perhaps related to Middle English welten "to overturn, roll over" (c. 1300), from Old Norse velta "to roll" (related to welter (v.)). Meaning "ridge on the skin from a wound" is first recorded 1800.
weltanschauung (n.): 1868 (William James), from German Weltanschauung, from welt "world" (see world) + anschauung "perception" (related to English show).
welter (v.): "to roll or twist," early 14c., from Middle Dutch or Middle Low German welteren "to roll," from Proto-Germanic *waltijan (source also of Old English wieltan, Old Norse velta, Old High German walzan "to turn, revolve," German wälzen "to roll," Gothic waltjan "to roll"), from PIE root *wel- (3) "to turn, revolve" (see volvox). Related: Weltered; weltering.
welter (n.): 1590s, "confusion," from welter (v.). The meaning "confused mass" is first recorded 1851.
welterweight (n.): 1831, "heavyweight horseman," later "boxer or wrestler of a certain weight" (1896), from earlier welter "heavyweight horseman or boxer" (1804), possibly from welt (v.) "beat severely" (c. 1400).
... but at the end of the first German mile, Nature gave way, and this excellent mare was obliged to "knock under" to the extraordinary exertions she had made, and to the welter weight she carried, upwards of 13 stone. ["The Sporting Magazine," September 1831]
weltschmerz (n.): "pessimism about life," 1872 (1863 as a German word in English), from German Weltschmerz, coined 1810 by Jean Paul Richter, from Welt "world" (see world) + Schmerz "pain" (see smart (n.)). Popularized in German by Heine.
wen (n.): Old English wenn "a wen, tumor, wart," from Proto-Germanic *wanja- "a swelling" (source also of Middle Low German wene, Dutch wen, dialectal German Wenne), from PIE *wen- (2) "to beat, wound" (see wound (n.)).
Wenceslas: masc. proper name, from Medieval Latin Venceslaus (modern Czech Vaclav), from Old Czech Veceslavŭ, literally "having greater glory," from Slavic *vetye- "greater" + *-slavu "fame, glory," from PIE *klou-, from root *kle- "to hear" (see listen (v.)).
wench (n.): late 13c., wenche "girl, young woman," especially if unmarried, also "female infant," shortened from wenchel "child," also in Middle English "girl, maiden," from Old English wencel, probably related to wancol "unsteady, fickle, weak," from Proto-Germanic *wankila- (source also of Old Norse vakr "child, weak person," Old High German wanchal "fickle"), from PIE *weng- "to bend, curve" (see wink (v.)).
The wenche is nat dead, but slepith. [Wyclif, Matt. ix:24, c. 1380]
In Middle English occasionally with disparaging suggestion, and secondary sense of "concubine, strumpet" is attested by mid-14c. Also "serving-maid, bondwoman, young woman of a humble class" (late 14c.), a sense retained in the 19c. U.S. South in reference to slave women of any age. In Shakespeare's day a female flax-worker could be a flax-wench, flax-wife, or flax-woman.
wench (v.): "to associate with common women," 1590s, from wench (n.). Related: Wenched; wencher; wenching.
wend (v.): "to proceed on," Old English wendan "to turn, direct, go; convert, translate," from Proto-Germanic *wanjan (source also of Old Saxon wendian, Old Norse venda, Swedish vända, Old Frisian wenda, Dutch wenden, German wenden, Gothic wandjan "to turn"), causative of PIE *wendh- "to turn, wind, weave" (see wind (v.1)). Surviving only in to wend one's way, and in hijacked past tense form went. Originally weak; strong past participle is from c. 1200.
Wend (n.): member of a Slavic people of eastern Germany, 1610s (implied in Wendish), from German Wende, from Old High German Winida, related to Old English Winedas "Wends," of uncertain origin. Perhaps ultimately from Celtic *vindo- "white," or from PIE *wen-eto- "beloved," from *wen- (1) "to desire." Related: Wendish.
Wendy: as a woman's given name, apparently coined by James M. Barrie ("Peter and Wendy," 1911); it first registers on the U.S. Social Security list of popular baby names in 1936 and was in the top 40 names for girls born in the U.S. from 1965 to 1976
went (v.): past tense of go; originally the strong past tense and past participle of wend (v.). The original past tense forms of wend were wende, wended, but variants wente, went developed from c. 1200 and these then began to replace older past tenses of go. By c. 1500 they were fully employed in that function, and wend was given a new past tense form, wended.
were (v.): Old English wæron (past plural indicative of wesan) and wære (second person singular past indicative); see was. The forms illustrate Verner's Law (named for Danish linguist Karl Verner, 1875), which predicts the "s" to "z" sound shift, and rhotacism, which changed "z" to "r." Wast (second person singular) was formed 1500s on analogy of be/beest, displacing were. An intermediate form, wert, was used in literature 17c.-18c., before were reclaimed the job.
werewolf (n.): late Old English werewulf "person with the power to turn into a wolf," from wer "man, male person" (from PIE *wi-ro- "man, freeman;" see virile) + wulf (see wolf (n.); also see here for a short discussion of the mythology). Belief in them was widespread in the Middle Ages. Similar formation in Middle Dutch weerwolf, Old High German werwolf, Swedish varulf. In the ancient Persian calendar, the eighth month (October-November) was Varkazana-, literally "(Month of the) Wolf-Men."
wergeld (n.): "set sum of money as the value of a free man, based on social rank, and paid as compensation for his murder or injury in discharge of punishment or vengeance," Old English wergeld (Anglian, Kentish), wergield (West Saxon), from wer "man" (see virile) + geld "payment, tribute" (see geld (n.)).
Werther: love-lorn hero of Goethe's "Die Leiden des jungen Werthers" ("The Sorrows of Young Werther"), popular and influential short novel published in 1774. His name was used as a type of morbid sentimentality.
Wesleyan (adj.): "pertaining to Wesley," 1771, in reference to John Wesley (1703-1791), founder of Methodism. The surname is from various places in England named West Leigh (or some variant). Related: Wesleyanism.
Wessex: Anglo-Saxon kingdom in southern England, literally "(land of the) West Saxons;" see west + Saxon. Modern use in reference to southwestern England (excluding Cornwall) is from Hardy's novels.
west: Old English west (adv.) "in or toward the west, in a westerly direction," from Proto-Germanic *west- (source also of Old Norse vestr, Old Frisian, Middle Dutch, Dutch west, Old High German -west, only in compounds, German west), from PIE *wes-, reduced form of *wes-pero- "evening, night" (source also of Greek hesperos, Latin vesper "evening, west;" see vesper). Compare also High German dialectal abend "west," literally "evening." French ouest, Spanish oeste are from English.

As an adjective from late 14c.; as a noun from late 12c. West used in geopolitical sense from World War I (Britain, France, Italy, as opposed to Germany and Austria-Hungary); as contrast to Communist Russia (later to the Soviet bloc) it is first recorded in 1918. West Coast of the U.S. is from 1850; West End of London is from 1776; West Side of Manhattan is from, 1858. The U.S. West "western states and territories" originally (1790s) meant those just west of the Alleghenies; the sense gradually extended as the country grew. To go west "die" was "common during the Great War" [OED, 2nd ed.], perhaps from Celtic imagery or from the notion of the setting sun. In U.S. use, in a literal sense "emigrate to the western states or territories," from 1830.
West Bank: in reference to the former Jordanian territory west of the River Jordan, 1967.
West Indies: Caribbean islands explored by Columbus, 1550s, reflecting the belief (or hope) that they were western outliers of the Indies of Asia. Related: West Indian, which is from 1580s in reference to the native inhabitants, 1650s in reference to European settlers there, and 1928 in reference to people of West Indian ancestry.
wester (v.): "to go west, travel westward," late 14c., from west (adv.), and compare westerly. Related: Westered; westering.
westerlies (n.): prevailing winds in certain latitudes, 1876, from westerly (see west).
westerly (adv.): late 15c., "in a westerly direction; facing toward the west," from Middle English wester (adj.) "western" (mid-14c.), from Old English westra, variant of westerne (see western) + -ly (2). As an adjective, "coming from the west," 1570s. Contradictory sense of "going to the west" attested by 1630s.
western (adj.): "toward or of the west," late Old English westerne "western, westerly, coming from the west," from west + -erne, suffix denoting direction. The noun meaning "book or movie about the Old West" is first attested 1909. Westerner is from 1837 as "person from the U.S. West," 1880 as "Euro-American," as opposed to Oriental.
westernization (n.): also westernisation, 1873, noun of action from westernize (v.). Earliest reference is to Japan.
[The mikado's] late rapid and radical progress in westernization (to evolve a word that the Japanese will need) justifies great expectations of him. [Coates Kinney, "Japanning the English Language," "The Galaxy," July-Dec. 1873]
westernize (adj.): also westernise, 1837, originally in reference to the U.S. West, from western + -ize.
Emigrants from Europe have brought the peculiarities of the nations and countries from whence they have originated, but are fast losing their national manners and feelings, and, to use a provincial term, will soon become "westernized." [J.M. Peck, "A New Guide for Emigrants to the West," Boston, 1837]
In reference to Europeanizing of Middle Eastern or Asian places and persons, from 1867. Related: Westernized; westernizing.
westernmost (adj.): 1550s, from western + -most.
Westphalia: former duchy of Germany; the treaties which ended the Thirty Years War were signed there Oct. 24, 1648. Related: Westphalian.
westward (adv.): "toward the west," Old English westweard; see west + -ward.
wet (adj.): Old English wæt "moist, rainy, liquid," also as a noun. "moisture, liquid drink," from Proto-Germanic *weta- (source also of Old Frisian wet ). Also from cognate Old Norse vatr; all from PIE *wed- (1) "water, wet" (see water (n.1)). Of paint, ink, etc., "not yet dry" from 1510s. Opposed to dry in reference to the U.S. battles over prohibition from 1870. Wet blanket "person who has a dispiriting effect" is recorded from 1871, from use of blankets drenched in water to smother fires (the phrase is attested in this literal sense from 1660s).
Do we not know them, those wet blankets who come down on our pleasant little fires and extinguish them, with no more ruth than the rain feels when it pours on the encampment of the merry picnic party, or floods the tents of a flower show? ["Wet Blankets," in "Godey's Lady's Book and Magazine," February, 1871]
All wet "in the wrong" is recorded from 1923, American English; earlier simply wet "ineffectual," and perhaps ultimately from slang meaning "drunken" (c. 1700). Wet-nurse is from 1610s. The diver's wet-suit is from 1955. Wet dream is from 1851; in the same sense Middle English had ludificacioun "an erotic dream."
He knew som tyme a man of religion, þat gaff hym gretelie vnto chastitie bothe of his harte & of his body noghtwithstondyng he was tempid with grete ludificacions on þe nyght. ["Alphabet of Tales," c. 1450]
wet (v.): Old English wætan "to wet, moisten, water; be or become wet;" see wet (adj.). From mid-15c. as "to intoxicate" (oneself). Meaning "urinate" is by 1925. Related: Wetted; wetting.
wet (n.): Old English wæt (see wet (adj.)).
wetback (n.): "illegal Mexican immigrant to the U.S.," c. 1924, from wet (adj.) + back (n.); from notion of wading the Rio Grande.
wether (n.): "male sheep," especially a castrated one, Old English weðer "ram," from Proto-Germanic *wethruz (source also of Old Saxon wethar, Old Norse veðr, Old High German widar, German Widder, Gothic wiþrus "lamb"), literally "yearling," from PIE root *wet- (2) "year" (source also of Sanskrit vatsah "calf," Greek etalon "yearling," Latin vitulus "calf," literally "yearling").
wetland (n.): 1743, from wet (adj.) + land (n.).
wetness (n.): Old English wetnise; see wet (adj.) + -ness.
wey (n.): dry goods weight of fixed amount (but varying over time and place), Old English weg "scales, balance, weight" (see weigh).
wh-: respelling of Old English hw- attested from 11c., but not the common form until after c. 1400. It represents PIE *kw-; in German reduced to simple w-, in Scandinavian as hv-, kv-, or v-.

Also added to some borrowed words (whisk, whiskey) and some native words formerly spelled with simple w- or h- (whole, whore). In the 15c. flowering of its use it also threatened to change the spelling of hot, home and many more. In northern English 16c.-18c., sometimes altered to quh- (see Q). Proper pronunciation has been much in dispute in educated speech.
whack (v.): "to strike sharply," 1719, probably of imitative origin. The noun is from 1737. The word in out of whack (1885) is perhaps the slang meaning "share, just portion" (1785), which may be from the notion of the blow that divides, or the rap of the auctioneer's hammer. To have (or take) a whack at something "make an attempt" is from 1891. Related: Whacked; whacking. Whacked out is from 1969.