Source : Webster's Revised Unabridged Dictionary (1913)

Petrify \Pet"ri*fy\, v. t. [imp. & p. p. {Petrified}; p. pr. &
   vb. n. {Petrifying}.] [L. petra rock, Gr. ? (akin to ? a
   stone) + -fy: cf. F. p['e]trifier. Cf. {Parrot}, {Petrel},
   {Pier}.]
   1. To convert, as any animal or vegetable matter, into stone
      or stony substance.

            A river that petrifies any sort of wood or leaves.
                                                  --Kirwan.

   2. To make callous or obdurate; to stupefy; to paralyze; to
      transform; as by petrifaction; as, to petrify the heart.
      Young. ``Petrifying accuracy.'' --Sir W. Scott.

            And petrify a genius to a dunce.      --Pope.

            The poor, petrified journeyman, quite unconscious of
            what he was doing.                    --De Quincey.

            A hideous fatalism, which ought, logically, to
            petrify your volition.                --G. Eliot.

Source : WordNet®

petrifying
     adj : paralyzing with terror