Other forms: birds
A bird is an animal with feathers and wings. A small bird, birds sing, bird watching.
Feathers are the one thing all birds have and nothing else does. There are about eleven thousand species and they are the surviving dinosaurs, which is settled science rather than a curiosity. Not all of them fly. Note a bird in the hand; kill two birds with one stone; the birds and the bees; and that bird is dated British slang for a young woman, now generally avoided.
1nounbirdAn animal with feathers and wings.
“A little bird was singing in the tree outside my window.”
bird is an animal.
Old English bridd meant a chick or fledgling, and the general word for a flying bird was fugol, which survives as fowl. The young bird's word won and the adult's word narrowed to poultry.
Middle English
brid
English, today
bird
From Middle English brid. From Middle English bird, brid, from Old English bridd (“chick, fledgling, chicken”), of unknown origin (see 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. 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.
Etymology from Wiktionary, CC BY-SA