Source : Webster's Revised Unabridged Dictionary (1913)

Theodicy \The*od"i*cy\, n. [NL. theodic[ae]a, fr. Gr. ? God + ?
   right, justice: cf. F. th['e]odic['e]e.]
   1. A vindication of the justice of God in ordaining or
      permitting natural and moral evil.

   2. That department of philosophy which treats of the being,
      perfections, and government of God, and the immortality of
      the soul. --Krauth-Fleming.

Source : WordNet®

theodicy
     n : the branch of theology that defends God's goodness and
         justice in the face of the existence of evil