flap / flap/ • v. (flapped, flap·ping) [tr.] (of a bird) move (its wings) up and down when flying or preparing to fly: a pheasant flapped its wings | [intr.] gulls flapped around uttering their strange cries. ∎  [intr.] (of something attached at one point or loosely fastened) flutter or wave around: the tent bent with the gale, and the corners flapped furiously. ∎  move (one's arms or hands) up and down or back and forth: she began flapping her arms to drive away the permeating cold. ∎  [tr.] strike or attempt to strike (something) loosely with one's hand, a cloth, or a broad implement, esp. to drive it away: they flap away the flies with peacock tails. ∎  wave (something, esp. a cloth) around or at something or someone: she flapped the duster angrily.• n. 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. ∎  a hinged or sliding section of an aircraft wing used to control lift: flaps are normally moved by the hydraulics | a final approach at sixty knots with 45° of flap. ∎  the part of a dust jacket that folds inside a book's cover, on which a summary of the book or a biographical sketch of the author is typically printed: I read a book jacket flap that said that the author lived with her husband in Connecticut. ∎  a large broad mushroom. ∎  Phonet. a type of consonant produced by allowing the tip of the tongue to strike the alveolar ridge very briefly.2. a movement of a wing or an arm from side to side or up and down: the surviving bird made a few final despairing flaps. ∎  [in sing.] the sound of something making such a movement: hear the coo of the dove, the flap of its wings.3. [in sing.] inf. a state of agitation; a panic: they're in a flap over who's going to take Henry's lectures.DERIVATIVES: flap·py adj.

flap (flap) n. (in surgery) a strip of tissue dissected away from the underlying structures but left attached at one end so that it retains its blood and nerve supply in a pedicle. The flap is then used to repair a defect in another part of the body or to cover the end of a bone in an amputated limb. It is detached from its original site when it has healed into the new one.

flap †blow XIV; fly-flapper XV; loose pendent part XVI. flap vb. strike with something flexible and broad XIV; (of birds) beat the wings XVI. prob. imit.; cf. Du. flap blow, fly-flapper, lid of a can, flappen strike, clap.
Hence flapper one who or that which flaps XVI; young partridge XIX (hence sl., young woman XX).

Flap

of nuns—Lipton, 1970.