assassin

Noun

• a member of a secret order of Muslims (founded in the 12th century) who terrorized and killed Christian Crusaders

• a murderer (especially one who kills a prominent political figure) who kills by a surprise attack and often is hired to do the deed
  • his assassins were hunted down like animals
    
  • assassinators of kings and emperors
    

Related words

• Synonyms: 
  assassinator , bravo