Gaggle
Middle English (as a verb): imitative of the noise that a goose makes; compare with Dutch gaggelen and German gackern .
wiktionary
From Middle English gagelen(“to cackle; cackle like a goose”). Compare Dutch gaggelen(“to cackle”), Icelandic gagl(“small goose; gosling”).
etymonline
gaggle (n.)
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.