fowlyoudaoicibaDictYouDict[fowl 词源字典]
fowl: [OE] Fowl was the main term for ‘bird’ in the Old English period, but in Middle English it was gradually replaced by bird. (It remains in use in compounds, such as wildfowl and waterfowl, and is sometimes still applied to ‘chickens’.) It goes back to a prehistoric Germanic *foglaz or *fuglaz, which also produced the still very much current German and Dutch vogel, Swedish fåagel, and Danish fugl, all signifying ‘bird’, and which may have been a derivative of the same source (*fleug-) as gave English fly – in which case fowl would mean literally ‘flying creature’.
=> fly[fowl etymology, fowl origin, 英语词源]
fowl (n.)youdaoicibaDictYouDict
Old English fugel "bird, feathered vertebrate," from Proto-Germanic *fuglaz, the general Germanic word for "bird" (cognates: Old Saxon fugal, Old Frisian fugel, Old Norse fugl, Middle Dutch voghel, Dutch vogel, German vogel, Gothic fugls "a fowl, a bird"), perhaps a dissimilated form meaning literally "flyer," from PIE *pleuk- (see fly (v.1)).

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.
fowl (v.)youdaoicibaDictYouDict
Old English fuglian "to catch birds," from the source of fowl (n.). Related: Fowled; fowling. Fowling-piece "gun used for shooting wildfowl" is from 1590s.