late 15c., gagyll, with reference to both geese and women. Barnhardt says possibly from O.N. gagl "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 (cf. Du. gagelen "to chatter;" M.E. gaggle "to cackle," used of geese, attested from late 14c.).