1. To strike one's hands together; SYN. spat.
2. To strike together so as to produce a sharp percussive noise, as of two flat, hard surfaces.
3. To strike with the flat of the hand; usually in a friendly way, as in encouragement or greeting.
4. To strike the air in flight; said of the wings of certain birds.
5. To put quickly or forcibly.

ETYM Cf. Old Fren. clapoir.
A loud sound, such as that made by hands clapping together.

(Slang) Venereal disease.
GONORRHEA — often used with the.