Webster's English Dictionary

vengeance

ven.geance \'ven-j*n(t)s\ n [ME, fr. OF, fr. vengier to avenge, fr. L 
   vindicare to lay claim to], avenge - more at VINDICATE : punishment 
   inflicted in retaliation for an injury or offense : RETR IBUTION 1: 
   VIOLENTLY  2: EXTREMELY  - with a vengeance