Definition of clack

• n. - To make a sudden, sharp noise, or a succesion of such noises, as by striking an object, or by collision of parts; to rattle; to click.
• n. - To utter words rapidly and continually, or with abruptness; to let the tongue run.
• v. t. - To cause to make a sudden, sharp noise, or succession of noises; to click.
• v. t. - To utter rapidly and inconsiderately.
• v. t. - A sharp, abrupt noise, or succession of noises, made by striking an object.
• v. t. - Anything that causes a clacking noise, as the clapper of a mill, or a clack valve.
• v. t. - Continual or importunate talk; prattle; prating.