aggressor
I
noun
antagonist, assailant, assailer, assaulter, attacker, belligerent, besieger, combatant, contender, criminal, fighter, foe, initiative seizer, invader, militant, prime mover, provocator, ravager, ruffian, stormer, violator
II
index
assailant, offender
Burton's Legal Thesaurus.
William C. Burton.
2006