tire iron

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

• noun A tool consisting of a metal bar having one end shaped like a chisel and often the other in the form of a socket wrench, used for changing tires on most motor vehicles.

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

• noun a short steel bar with one end flattened so as to form a blade, used to remove rubber tires from the rim of a wheel.

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

• noun a solid bar with a chisel end and a socket wrench end used for replacing tires

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

• noun hand tool consisting of a lever that is used to force the casing of a pneumatic tire onto a steel wheel