car bomb

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

• noun An explosive device that is placed in a motor vehicle and detonated in order to kill people or destroy nearby property, especially as an act of terrorism.

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

• noun An automobile laden with a large amount of explosives, and used as a bomb primarily in order to cause external damage.
• noun An explosive device installed in an automobile with the primary purpose to kill the occupants of the car.
• noun slang Flatulence in an enclosed automobile.
• noun An alcoholic beverage made by dropping a shot of liquor into a glass of beer.

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

• noun a bomb placed in a car and wired to explode when the ignition is started or by remote control or by a timing device