Origin and history of vindicator

mid-15c., vendicacion, "act of avenging, revenge; assertion of a claim" (senses now obsolete); 1640s as "justification by proof, defense against censure;" from Old French vindicacion "vengeance, revenge" and directly from Latin vindicationem (nominative vindicatio) "act of claiming or avenging," noun of action from past-participle stem of vindicare "lay claim to, assert; claim for freedom, set free; protect, defend; avenge" (related to vindicta "revenge"). This is held to be probably from vim dicare "to show authority," from vim, accusative of vis "force" (see vim) + dicare "to proclaim" (see diction).