Akademik

clack

v. & n.
—v.intr.
1 make a sharp sound as of boards struck together.
2 chatter, esp. loudly.
—n.
1 a clacking sound.
2 clacking talk.
Derivatives:
clacker n.
Etymology: ME, = to chatter, prob. f. ON klaka, of imit. orig.

Useful english dictionary. 2012.