WordNet (r) 3.0 (2006):

self-protection
    n 1: the act of defending yourself [syn: self-defense, self-
         defence, self-protection]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "self-protection":
   avoidance reaction, defence, defense, defense in depth,
   defense mechanism, defenses, deterrent capacity, ego defenses,
   escape mechanism, guard, negative taxis, protection,
   psychological defenses, resistance, self-defense,
   self-preservation, the defensive, ward