eutychian

from The Century Dictionary.

• Of or pertaining to Eutyches or his doctrine.
• noun A follower or one holding the doctrine of Eutyches, a monk of Constantinople in the fifth century, who taught that Christ had but one nature, the divine, so that it was proper to say that God had been crucified for us. He was an opponent of Nestorius, and the founder of the sect of Monophysites. See Monophysite.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Eccl. Hist.) A follower of Eutyches [5th century], who held that the divine and the human in the person of Christ were blended together as to constitute but one nature; a monophysite; -- opposed to Nestorian.