Clacker is a colloquial and informal term used to refer to a device that produces a loud clacking sound, typically made by rattling two hard objects together. However, there are several other synonyms you can use instead of clacker, such as clapper, rattle, noise maker, castanet, clicker, cracker, and snap. Clacker is commonly used to describe the sound produced by instruments like castanets, rattles, and noise makers. Clicker, cracker, and snap usually refer to small, handheld toys that produce a clicking sound when pressed or activated. On the other hand, a clapper is a device that produces a loud, rhythmical sound when struck together, usually to signal the start or end of a performance.