What is the meaning of Clack?

An abrupt, sharp sound, especially one made by two hard objects colliding repetitively; a sound midway between a click and a clunk.

Anything that causes a clacking noise, such as the clapper of a mill, or a clack valve.

Chatter; prattle.

The tongue.

To make a sudden, sharp noise, or succession of noises; to click.

To cause to make a sudden, sharp noise, or succession of noises; to click.

To chatter or babble; to utter rapidly without consideration.

To cut the sheep's mark off (wool), to make the wool weigh less and thus yield less duty.

Dated form of cluck.

Source: wiktionary.org