assault weapon

Noun

 * 1)  Any select-fire firearm that allows semi-automatic and fully automatic operation, and is used or was once used by a military organization.
 * 2)  A semi-automatic firearm that resembles a military weapon.
 * 3)  A semi-automatic weapon that has a folding stock, a muzzle flash suppressor, a bayonet mount, or a pistol grip.
 * 4)  A rocket launcher designed to attack fortified structures, such as a Mk 153 Shoulder-Launched Multipurpose Assault Weapon (aka SMAW).

Usage notes

 * This term is considered pejorative by some. It is used primarily in the context of discussions of gun-control policy.
 * There is no universally accepted definition of an assault weapon, and the meaning varies between jurisdictions. However, according to defunct United States federal legislation, any semi-automatic rifle is an assault weapon if it has a detachable magazine and has two or more of the following: pistol grip, folding or telescoping stock, bayonet mount, flash suppressor, grenade launcher.
 * Compare.