1. Attack, assail, assault, molest all mean to set upon someone forcibly, with hostile or violent intent. Attack is the most general word and applies to a beginning of hostilities, especially those definitely planned: to attack from ambush. Assail implies vehement, sudden, and sometimes repeated attack: to assail with weapons or with gossip. Assault almost always implies bodily violence: to assault with intent to kill. To molest is to harass, to threaten, or to assault: He was safe, and where no one could molest him.

Did you mean stacking?