rocker

rocker is a Noun

Definition:

[1] One who rocks; specifically, one who rocks a cradle. It was I, sir, said the rocker, who had the honor, some thirty years since, to attend on your highness in your infancy. Fuller.

[2] One of the curving pieces of wood or metal on which a cradle, chair, etc., rocks.

[3] 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.

[4] A play horse on rockers; a rocking-horse.

[5] A chair mounted on rockers; a rocking-chair.

[6] A skate with a curved blade, somewhat resembling in shape the rocker of a cradle.

[7] Same as Rock shaft. Rocker arm (Mach.), an arm borne by a rock shaft. To be off one`s rocker, to be insane.