Real Dictionary

flock
A flock of birds, sheep, or goats is a group of them.
You can refer to a group of people or things as a flock of them to emphasize that there are a lot of them.

flock in American English 1
a group of certain animals, as goats or sheep, or of birds, living, feeding, or moving together
to assemble or travel in a flock or crowd
intransitive verb: to gather or go in a flock or crowd
noun: a number of animals of one kind, esp. sheep, goats, or birds, that keep or feed together or are herded together

flock in American English 2
a small tuft of wool, cotton, etc.
to stuff or decorate with flock
noun: a lock or tuft of wool, hair, cotton, etc
transitive verb: to stuff with flock, as a mattress

flock in British English 1
a group of animals of one kind, esp sheep or birds
to gather together or move in a flock

flock in British English 2
noun: a tuft, as of wool, hair, cotton, etc