one who rocks; specifically, one who rocks a cradle.-one of the curving pieces of wood or metal on which a cradle, chair, etc., rocks.-any implement or machine working with a rocking motion, as a trough mounted on rockers for separating gold dust from gravel, etc., by agitation in water.-a play horse on rockers; a rocking-horse.-a chair mounted on rockers; a rocking-chair.-a skate with a curved blade, somewhat resembling in shape the rocker of a cradle.-same as rock shaft.