Source : Webster's Revised Unabridged Dictionary (1913)

Selflessness \Self"less*ness\, n.
   Quality or state of being selfless.

Source : WordNet®

selflessness
     n 1: the quality of unselfish concern for the welfare of others
          [syn: {altruism}] [ant: {egoism}]
     2: acting with less concern for yourself than for the success
        of the joint activity [syn: {self-sacrifice}]