The Collaborative International Dictionary of English v.0.48:

Self-preservation \Self`-pres`er*va"tion\, n.
   The preservation of one's self from destruction or injury.
   [1913 Webster]

WordNet (r) 3.0 (2006):

self-preservation
    n 1: preservation of yourself from harm; a natural or
         instinctive tendency

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "self-preservation":
   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-protection,
   the defensive, ward