Source : Webster's Revised Unabridged Dictionary (1913)

Altruism \Al"tru*ism\, n. [F. altruisme (a word of Comte's), It.
   altrui of or to others, fr. L. alter another.]
   Regard for others, both natural and moral; devotion to the
   interests of others; brotherly kindness; -- opposed to
   {egoism} or {selfishness}. [Recent] --J. S. Mill.

Source : WordNet®

altruism
     n : the quality of unselfish concern for the welfare of others
         [syn: {selflessness}] [ant: {egoism}]