assault weapon
noun1
US Any select-fire firearm that allows semi-automatic and fully automatic operation, and is used or was once used by a military organization.
2
US A semi-automatic firearm that resembles a military weapon.
3
US A semi-automatic weapon that has a folding stock, a muzzle flash suppressor, a bayonet mount, or a pistol grip.
4
US A rocket launcher designed to attack fortified structures, such as a Mk 153 Shoulder-Launched Multipurpose Assault Weapon (aka SMAW).