attack, onrush, onset, onslaught - (military) an offensive against an enemy (using weapons); "the attack began at dawn"

terrorist attack - a surprise attack involving the deliberate use of violence against civilians in the hope of attaining political or religious aims

ambuscade, ambush, lying in wait, trap - the act of concealing yourself and lying in wait to attack by surprise

pre-emptive strike - a surprise attack that is launched in order to prevent the enemy from doing it to you