Source : Webster's Revised Unabridged Dictionary (1913)

Self-deceit \Self`-de*ceit"\, n.
   The act of deceiving one's self, or the state of being
   self-deceived; self-deception.

Source : WordNet®

self-deceit
     n : a misconception that is favorable to the person who holds it
         [syn: {self-deception}]