Old English fugel "bird, feathered vertebrate," from Proto-Germanic *fuglaz, the general Germanic word for "bird" (source also of Old Saxon fugal, Old Frisian fugel, Old Norse fugl, Middle Dutch voghel, Dutch vogel, German vogel, Gothic fugls "a fowl, a bird"), perhaps a dissimilation of a word meaning literally "flyer," from PIE *pleuk-, from root *pleu- "to flow."
Displaced in its original sense by bird (n.); narrower sense of "barnyard hen or rooster" (the main modern meaning) is first recorded 1570s; in U.S. this was extended to domestic ducks and geese.
It forms all or part of: fletcher; fledge; flee; fleet (adj.) "swift;" fleet (n.2) "group of ships under one command;" fleet (v.) "to float, drift; flow, run;" fleeting; flight (n.1) "act of flying;" flight (n.2) "act of fleeing;" flit; float; flood; flotsam; flotilla; flow; flue; flugelhorn; fluster; flutter; fly (v.1) "move through the air with wings;" fly (n.) "winged insect;" fowl; plover; Pluto; plutocracy; pluvial; pneumo-; pneumonia; pneumonic; pulmonary.
It is the hypothetical source of/evidence for its existence is provided by: Sanskrit plavate "navigates, swims;" Greek plynein "to wash," plein "to navigate," ploein "to float, swim," plotos "floating, navigable," pyelos "trough, basin;" Latin plovere "to rain," pluvius "rainy;" Armenian luanam "I wash;" Old English flowan "to flow;" Old Church Slavonic plovo "to flow, navigate;" Lithuanian pilu, pilti "to pour out," plauju, plauti "to swim, rinse."
"feathered, warm-blooded vertebrate animal of the class Aves," Old English bird, rare collateral form of bridd, originally "young bird, nestling" (the usual Old English for "bird" being fugol, for which see fowl (n.)), which is of uncertain origin with no cognates in any other Germanic language. The suggestion that it is related by umlaut to brood and breed is rejected by OED as "quite inadmissible." Metathesis of -r- and -i- was complete 15c. (compare wright).
Despite its early attestation, bridd is not necessarily the oldest form of bird. It is usually assumed that -ir- from -ri- arose by metathesis, but here, too, the Middle English form may go back to an ancient period. [Liberman]
Still up to c. 1400 it was often used in the specific sense "the young of a bird, fledgling, nestling, chick," and of the young of other animals (bees, fish, snakes) and human children. Compare the usual Balto-Slavic words for "bird" (Lithuanian paukštis, Old Church Slavonic pŭtica, Polish ptak, Russian ptica, etc.), said to be ultimately from the same root as Latin pullus "young of an animal."
The proper designation of the feathered creation is in E. fowl, which in course of time was specially applied to the gallinaceous tribe as the most important kind of bird for domestic use, and it was perhaps this appropriation of the word which led to the adoption of the name of the young animal as the general designation of the race. [Hensleigh Wedgwood, "A Dictionary of English Etymology," 1859]
Figurative sense of "secret source of information" is from 1540s. Meaning "man, fellow, person" is from 1799. Bird-watching attested from 1897. Bird's-eye view "the view as seen from above, as if by a bird in flight," is from 1762. For the birds recorded from 1944, supposedly in allusion to birds eating from droppings of horses and cattle. The bird-spider (1800) of the American tropics is a large sort of tarantula that can capture and kill small birds.
A byrde yn honde ys better than three yn the wode. [c. 1530]
The form with bush is attested by 1630s.
"domestic fowls collectively," late 14c., pultry (mid-14c. as "place where poultry is sold," also the name of a street in London), from Old French pouletrie "domestic fowl" (13c.), from pouletier "dealer in domestic fowl," from poulet "young fowl" (from PIE root *pau- (1) "few, little"). Also from Medieval Latin pultria, pulteria.
late 14c., polet, "young fowl" (late 13c. as a surname), from Anglo-French pullet, Old French poulette, poilette, diminutive of poule, poille "hen," from Vulgar Latin *pulla, fem. of Latin pullus "young animal," especially "young fowl" (source also of Spanish pollo "chicken," Italian pollo "fowl;" from PIE root *pau- (1) "few, little." Compare pony.
A cockerel is a male bird under one year old, a cock over one year old. A hen is a female over one year old and a pullet under one year old. [U.S. Department of Agriculture, "Practical Poultry Production," 1920]