The Collaborative International Dictionary of English v.0.48:

Retaliation \Re*tal`i*a"tion\, n.
   The act of retaliating, or of returning like for like;
   retribution; now, specifically, the return of evil for evil;
   e.g., an eye for an eye, a tooth for a tooth.
   [1913 Webster]

         God . . . takes what is done to others as done to
         himself, and by promise obloges himself to full
         retaliation.                             --Calamy.
   [1913 Webster]

   Syn: Requital; reprisal; retribution; punishment.
        [1913 Webster]

WordNet (r) 3.0 (2006):

retaliation
    n 1: action taken in return for an injury or offense [syn:
         retaliation, revenge]

The Devil's Dictionary (1881-1906):

RETALIATION, n.  The natural rock upon which is reared the Temple of
Law.