rocker

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun One that rocks, as.
• noun A rocking chair.
• noun A rocking horse.
• noun One of the two curved pieces upon which a cradle, rocking chair, or similar device rocks.
• noun A cradle used for washing or panning ores.
• noun A small curved blade with a toothed edge used in mezzotint engraving to roughen the surface of the metal plate.
• noun An object having a curved form, as the keel of a ship or a skate blade sharpened in a curve.
• noun A curved stripe at the bottom part of a chevron worn by noncommissioned officers above the rank of sergeant.
• noun A rock song, singer, or musician.
• noun A fan of rock music.
• idiom (off (one's) rocker) Out of one's mind; crazy.

from The Century Dictionary.

• noun The rock-dove, Columba livia. Montagu. Also rockier, rock.
• noun In pianoforte-making, the piece screwed to a key-tail to which the action-extension is fastened.
• noun A tanning-vat in which the hides are rocked at intervals to facilitate tanning.
• noun One who or that which rocks.
• noun The curved piece of wood on which a cradle or rocking-chair rocks.
• noun A rocking-horse.
• noun A rocking-chair.
• noun In engraving, same as cradle, 4 .
• noun A rocker-shaft.
• noun In mining, same as cradle 4 .
• noun In an electric-lamp regulator, a lever, pivoted in the middle, carrying at its extremities the armatures of two electromagnets, by the alternate attraction of which the carbon rods are made to separate or to approach each other.
• noun A boat or yacht having a rocker keel.
• noun A skate in which the bottom of the runner is not straight, but is convex from toe to heel.
• noun A vessel for freezing chemical mixtures, essentially a freezer mounted on rockers.
• noun In a railway gravel tip-car, a curved iron casting which supports the car-body, and on which the body rocks when the load is dumped.
• noun One of two beams used in the body-frame of a carriage to support the floor-boards. See cut under barouche.

from the GNU version of the Collaborative International Dictionary of English.

• noun One who rocks; specifically, one who rocks a cradle.
• noun One of the curving pieces of wood or metal on which a cradle, chair, etc., rocks.
• noun 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.
• noun A play horse on rockers; a rocking-horse.
• noun A chair mounted on rockers; a rocking-chair.
• noun A skate with a curved blade, somewhat resembling in shape the rocker of a cradle.
• noun (Mach.) Same as Rock shaft.
• noun (Mach.) an arm borne by a rock shaft.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A curved piece of wood attached to the bottom of a rocking chair or cradle that enables it to rock back and forth.
• noun Hence, a rocking chair
• noun surfing The lengthwise curvature of a surfboard. (More rocker is a more curved board.)
• noun Someone passionate about rock music.
• noun A musician who plays rock music
• noun One who rocks something.
• noun UK A member of a British subculture of the 1960s, opposed to the mods, who dressed in black leather and were interested in 1950s music.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a performer or composer or fan of rock music
• noun a chair mounted on rockers
• noun an ice skate with a curved blade
• noun an attendant who rocks a child in a cradle
• noun a teenager or young adult in the 1960s who wore leather jackets and rode motorcycles
• noun a curved support that permits the supported object to rock to and fro
• noun a trough that can be rocked back and forth; used by gold miners to shake auriferous earth in water in order to separate the gold