a murderer (especially one who kills a prominent political figure) who kills by a treacherous surprise attack and often is hired to do the deed; "his assassins were hunted down like animals"; "assassinators of kings and emperors"
a member of a secret order of Muslims (founded in the 12th century) who terrorized and killed Christian Crusaders
ready and able to resort to force or violence; "pugnacious spirits...lamented that there was so little prospect of an exhilarating disturbance"- Herman Melville; "they were rough and determined fighting men"