v. & n.
v. (clapped, clapping) 1 a intr. strike the palms of one's hands together as a signal or repeatedly as applause. b tr. strike (the hands) together in this way. 2 tr. applaud or show one's approval of (esp. a person) in this way. 3 tr. (of a bird) flap (its wings) audibly. 4 tr. put or place quickly or with determination (clapped him in prison; clap a tax on whisky).
n. 1 the act of clapping, esp. as applause. 2 an explosive sound, esp. of thunder. 3 a slap, a pat. clap eyes on colloq. see. clap on the back = slap on the back. clapped out Brit. sl. worn out (esp. of machinery etc.); exhausted.
[ OE clappian throb, beat, of imit. orig. ]