A bomb is an explosive device, usually some kind of container, filled with explosive material, designed to cause destruction when set off. The explosion of the bomb has to be triggered, usually by a clock, a remote control, or some kind of sensor, usually pressure (altitude), radar, or contact.

Bombs are often used in warfare, and as part of terrorism. The most powerful bomb in existence is the hydrogen bomb, the most powerful non-nuclear bomb is the MOAB (Massive Ordnance Air Burst).

• BLU = Bomb/mine Live Unit
• GBU = Guided Bomb Unit
• LGB = Laser Guided Bomb
• C-4 = a variant of plastique explosive

• bomb disposal
• bomb threat
• car bomb
• cluster bomb
• dirty bomb
• gravity bomb
• grenade
• neutron bomb
• pipe bomb

• Bombs for Beginners

Much less destructive is a water bomb, a popular children's toy used both for cooling down during hot weather, and for pulling practical jokes.

The term bomb is often used as slang:

• It can be used to mean "really good," as in "It's bomb."" (also: "It's the bomb.") Similarly, it can be used to label something as being expensive, implying that expensive goods are of high quality.

• Bomb is also used in the sense of "going very quickly," as in "bombing along."

• The term old bomb is used to refer to an old automobile in very poor condition.

• Someone who tries and fails spectacularly at a task is often said to have bombed out; for example, a comedian who tells a joke which falls flat says that joke bombed.

• A motion picture or theatrical production which is a financial failure is often described as a bomb. Alternatively, some people use the term bomb to refer instead to films of particularly bad quality, irrelevant of financial concerns. In seeming contradiction to this, a blockbuster motion picture is a great financial success.