Assassin (Cain novel)
WordNet
noun
(1) 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"
(2) A member of a secret order of Muslims (founded in the 12th century) who terrorized and killed Christian Crusaders