late 15c., gagyll, with reference to both geese and women (on the notion of "chattering company"). Barnhart says possibly from Old Norse gagl "small goose, gosling, wild goose;" OED calls it "one of the many artificial terms invented in the 15th c. as distinctive collectives referring to particular animals or classes of persons." Possibly of imitative origin (compare Dutch gagelen "to chatter;" Middle English gaggle "to cackle," used of geese, attested from late 14c.). The loosened general sense of "group of people" is from 1946.
updated on February 02, 2015