Revenger
From BiblePortal Wikipedia
American Tract Society Bible Dictionary [1]
Or Avenger OF BLOOD, is a name given in Scripture to the man who had the right, according to the Jewish polity, of taking revenge on him who had killed one of his relations. If a man had been guilty of manslaughter involuntarily and without design, he fled to a city of refuge. See Cities Of Refuge .
King James Dictionary [2]
REVENG'ER, n.
1. One who revenges one who inflicts pain on another spitefully in return for an injury. 2. One who inflicts just punishment for injuries. Less proper.
Webster's Dictionary [3]
(n.) One who revenges.