Etymology
1. O.E.
bridd, originally "young bird" (the usual O.E. for "bird" being
fugol), of uncertain origin with no cognates in any other Gmc. language. The suggestion that it is somehow connected by umlaut to
brood and
breed is dismissed by OED as "quite inadmissible." Metathesis of
-r- and
-i- occurred 15c. Fig. sense of "secret source of information" is from 1546. Slang meaning "middle finger held up in a rude gesture" is from 1860s expression
give the big bird "to hiss someone like a goose," kept alive in vaudeville slang with sense of "to greet someone with boos, hisses, and catcalls" (1922), transferred 1960s to the "up yours" hand gesture (the rigid finger representing the hypothetical object to be inserted) on notion of defiance and contempt. Gesture itself seems to be much older (the human anatomy section of a 12c. Latin bestiary in Cambridge describes the middle finger as that "by means of which the pursuit of dishonour is indicated").
Bird-brain (1943) is suggestive of flightiness.
Bird-cage is from 1490.
Bird's-eye view is from 1762.
For the birds recorded from 1944, supposedly in allusion to birds eating from droppings of horses and cattle.
"A byrde yn honde ys better than three yn the wode." [c.1530]
2. Etymology tree
3. Old English bridd
4. Middle English brid
5. English bird
6. From Middle English bird, brid, from Old English bridd (“chick, fledgling, chicken”), of uncertain origin (see Old English bridd for more). Originally from a term used of birds that could not fly (chicks, fledglings, chickens) as opposed to the general Old English term for flying birds, fugol (modern fowl). Gradually replaced fowl as the most common term starting in the 14th century.
7. The "booing/jeering" and "vulgar hand gesture" senses derived from the expression “to give the big bird”, as in “to hiss someone like a goose”, dated in the mid‐18th century.