verb1. to make or cause to make a sound like that of two pieces of wood hitting each other
2. (intransitive) to jabber
3. a less common word for cluck
noun5. a person or thing that produces this sound
7. Also called: clack valve a simple nonreturn valve using either a hinged flap or a ball
Word origin
C13: probably from Old Norse
klaka to twitter, of imitative origin