motor vehicle

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

• noun A self-propelled wheeled conveyance, such as a car or truck, that does not run on rails.

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

• noun Any land-based means of transportation in the form of a machine that operates primarily through a motor consuming fuel in order to provide power to rotate the tires.

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

• noun a self-propelled wheeled vehicle that does not run on rails