0 a type of light rifle (= a gun with a long barrel that is fired from the shoulder) that can work as an automatic (= firing many bullets quickly without needing to press the trigger repeatedly) or semiautomatic (= firing one round of bullets when the trigger is pressed):
The gunman opened fire with an assault rifle before being shot dead by police.
The militia battled with insurgents, using rocket-propelled grenades and assault rifles.
The soldier was part of a patrol that came under fire from rocket-propelled grenades and assault rifles.
