Source : Webster's Revised Unabridged Dictionary (1913)

Excruciate \Ex*cru"ci*ate\, v. t. [imp. & p. p. {Excruciated};
   p. pr. & vb. n. {Excruciating}.]
   To inflict agonizing pain upon; to torture; to torment
   greatly; to rack; as, to excruciate the heart or the body.

         Their thoughts, like devils, them excruciate.
                                                  --Drayton.

Excruciating \Ex*cru"ci*a`ting\
   Torturing; racking. ``Excruciating pain.'' --V. Knox.
   ``Excruciating fears.'' --Bentley -- {Ex*cru"ci*a`ting*ly},
   adv.

Source : WordNet®

excruciating
     adj : extremely painful [syn: {agonizing}, {agonising}, {harrowing},
            {torturing}, {torturous}, {torturesome}]