Definition of agony:
(n) :
violent contest or striving; pain so extreme as to cause writhing or contortions of the body, similar to those made in the athletic contests in Greece; and hence, extreme pain of mind or body; anguish; paroxysm of grief; specifically, the sufferings of Christ in the garden of Gethsemane
"being in an agony he prayed more earnestly. --Luke xxii. 44."