Source : Webster's Revised Unabridged Dictionary (1913)

Self-interest \Self`-in"ter*est\, n.
   Private interest; the interest or advantage of one's self.

Source : WordNet®

self-interest
     n 1: taking advantage of opportunities without regard for the
          consequences for others [syn: {opportunism}, {self-seeking},
           {expedience}]
     2: attempting to get personal recognition for yourself
        (especially by unacceptable means) [syn: {egoism}, {egocentrism},
         {self-concern}, {self-centeredness}] [ant: {altruism}]