v. 1 slap, slat, beat, flail, wave, wag, waggle, flutter, thresh, thrash, oscillate, vibrate An ornithopter is an aeroplane that flaps its wings like a bird The Union Jack was flapping in the breeze.
n. 2 flapping, beat, wave, wag, waggle, flutter, oscillation With a flap of its wings, the bird flew away 3 fold, fly, lappet, lap, tail, tab Leave a flap of cloth to cover the pocket 4 upset, agitation, to-do, ado, commotion, panic, flurry, fuss, distress, Colloq state, tizzy, sweat, Brit kerfuffle She's in a flap about what to wear to the dance 5 quarrel, argument, dispute There was a big flap over which car model to buy