n. 1 piece of cloth, wood, etc. attached by one side esp. to cover a gap, e.g. a pocketcover, the folded part of an envelope, a tableleaf. 2 motion of a wing, arm, etc. 3 colloq. agitation; panic (in a flap). 4 aileron. 5 light blow with something flat. c flappy adj. [probably imitative]
