flap |flap|
verb ( flapped , flapping ) [ trans. ]
(of a bird) move (its wings) up and down when flying or preparing to fly : a pheasant flapped its wings | [ intrans. ] gulls flapped around uttering their strange cries.
• [ intrans. ] (of something attached at one point or loosely fastened) flutter or wave around : the tent bent with the gale, and the corners flapped furiously.

flap |flap| (with a little flapper….)
noun
1 a piece of something thin, such as cloth, paper, or metal, hinged or attached only on one side, that covers an opening or hangs down from something : the flap of the envelope | he pushed through the tent flap.

(little flapper… informal (in the 1920s) a fashionable young woman intent on enjoying herself and flouting conventional standards of )