Source : Webster's Revised Unabridged Dictionary (1913)

Nestorianism \Nes*to"ri*an*ism\, n.
   The doctrines of the nestorian Christians, or of Nestorius.

Source : WordNet®

Nestorianism
     n : the theological doctrine (named after Nestorius) that Christ
         is both the son of God and the man Jesus (which is
         opposed to Roman Catholic doctrine that Christ is fully
         God)