Words

aggressor

aggression

(əˈɡrɛʃənPronunciation for aggression)
  noun
    1 an attack or harmful action, esp an unprovoked attack by one country against another
    2 any offensive activity, practice, etc ■ an aggression against personal liberty
    3 psychology a hostile or destructive mental attitude or behaviour
  [C17: from Latin aggression-, from aggrēdi to attack]

aggressor (əˈɡrɛsəPronunciation for aggressor)
noun