steering wheel

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

• noun A wheel that controls steering, as on a boat or in an automotive vehicle.

from The Century Dictionary.

• noun The wheel by which the rudder of a ship is shifted and the ship steered.
• noun A wheel by which the driver of a motor-car alters the direction of the front or rear pair of wheels, thus steering the ear.

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

• noun A wheel-shaped control that is rotated by the driver to steer, existing in most modern land vehicles.

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

• noun a handwheel that is used for steering