flap

n 1: any broad thin and limber covering attached at one edge; hangs loose or projects freely; "he wrote on the flap of the envelope"

2: an excited state of agitation; "he was in a dither"; "there was a terrible flap about the theft" syn dither, pother, fuss, tizzy

3: the motion made by flapping up and down syn flapping, flutter, fluttering

4: a movable piece of tissue partly connected to the body 5: a movable airfoil that is part of an aircraft wing; used to increase lift or drag syn flaps

v 1: move in a wavy pattern or with a rising and falling motion; "The curtains undulated"; "the waves rolled towards the beach" syn roll, undulate, wave

2: move noisily; "flags flapped in the strong wind" 3: move with a thrashing motion; "The bird flapped its wings"; "The eagle beat its wings and soared high into the sky" syn beat

4: move with a flapping motion; "The bird's wings were flapping" syn beat

5: make a fuss; be agitated syn dither, pother 6: pronounce with a flap, of alveolar sounds also flapping, flapped

Source: WordNet. Princeton University