| Clacker 1. (n.) One who clacks; that which clacks; especially, the clapper of a mill. 2. (n.) A claqueur. See Claqueur. Thesaurus Entries Klaxon, boiler factory, boiler room, bull-roarer, catcall, cherry bomb, clack, clapper, cracker, cricket, firecracker, horn, noisemaker, rattle, rattlebox, siren, snapper, steam whistle, ticktack, whistle, whizgig, whizzer |