early 14c., apparently from Old English bylgan "to bellow," from an imitative PIE root *bhel- "to sound, roar." Originally of animals, especially cows and bulls; used of human beings since c. 1600. Related: Bellowed; bellowing. As a noun, "a loud, deep cry," from 1763.

"companion, comrade," c. 1200, from Old English feolaga "partner, one who shares with another," from Old Norse felagi, from fe "money" (see fee) + lag, from Proto-Germanic *lagam, from PIE root *legh- "to lie down, lay." The etymological sense of fellow seems to be "one who puts down money with another in a joint venture."

Meaning "one of the same kind" is from early 13c.; that of "one of a pair" is from c. 1300. Used familiarly since mid-15c. for "any man, male person," but not etymologically masculine (it is used of women, for example, in Judges xi.37 in the King James version: "And she said unto her father, Let this thing be done for me: let me alone two months, that I may go up and down upon the mountains, and bewail my virginity, I and my fellows").

Its use can be contemptuous or dignified in English and American English, and at different times in its history, depending on who used it to whom, it has carried a tinge of condescension or insult.

University senses (mid-15c., corresponding to Latin socius) evolved from notion of "one of the corporation who constitute a college" and who are paid from its revenues. Fellow well-met "boon companion" is from 1580s, hence hail-fellow-well-met as a figurative phrase for "on intimate terms."

In compounds, with a sense of "co-, joint-," from 16c., and by 19c. also denoting "association with another." Hence fellow-traveler, 1610s in a literal sense but in 20c. with a specific extended sense of "one who sympathizes with the Communist movement but is not a party member" (1936, translating Russian poputchik).

Fellow-countrymen formerly was one of the phrases the British held up to mock the Americans for their ignorance, as it is redundant to say both, until they discovered it dates from the 1580s and was used by Byron and others.

Middle English withi, from Old English wiðig "willow, willow twig," from Proto-Germanic *with- "willow," which is reconstructed to be from PIE root *wei- "to bend, twist." Compare withe.

Germanic cognates include Old Norse viðir, Danish vidje, Swedish vide, Old High German wida, German Weide "willow." Cognates outside Germanic might be Avestan vaeiti- "osier," Greek itea "willow," Latin vītis "vine," Lithuanian vytis "willow twig," Polish witwa, Welsh gwden "willow," Russian vitvina "branch, bough."

popular name of a type of common American shrub or small tree, by 1835, a country or children's word, from pussy (n.1) + willow. So called for the small and very silky catkins it produces in early spring. Also sometimes pussy-cat (1850).

"flexible and graceful," 1791, from willow + -y (2). Earlier "bordered or shaded by willows" (1751). Willowish is older (1650s) but in reference to the color of willow leaves. Related: Willowiness.

Proto-Indo-European root meaning "to turn, revolve," with derivatives referring to curved, enclosing objects.

It might form all or part of: archivolt; circumvolve; convoluted; convolution; devolve; elytra; evolution; evolve; Helicon; helicopter; helix; helminth; lorimer; ileus; involve; revolt; revolution; revolve; valve; vault (v.1) "jump or leap over;" vault (n.1) "arched roof or ceiling;" volte-face; voluble; volume; voluminous; volute; volvox; volvulus; vulva; wale; walk; wallet; wallow; waltz; well (v.) "to spring, rise, gush;" welter; whelk; willow.

It might also be the source of: Sanskrit valate "turns round," ulvam "womb, vulva;" Lithuanian valtis "twine, net," vilnis "wave," apvalus "round;" Old Church Slavonic valiti "roll, welter," vlŭna "wave;" Greek eluein "to roll round, wind, enwrap," eilein "twist, turn, squeeze; revolve, rotate," helix "spiral object;" Latin volvere "to turn, twist;" Gothic walwjan "to roll;" Old English wealwian "roll," weoloc "whelk, spiral-shelled mollusk;" Old High German walzan "to roll, waltz;" Old Irish fulumain "rolling;" Welsh olwyn "wheel."