Source : Webster's Revised Unabridged Dictionary (1913)

Trochlear \Troch"le*ar\, n. [L. trochlea block or pulley.]
   (Anat.)
   Shaped like, or resembling, a pulley; pertaining to, or
   connected with, a trochlea; as, a trochlear articular
   surface; the trochlear muscle of the eye.

   {Trochlear nerve}. See {Pathetic nerve}, under {Pathetic}.

Source : WordNet®

trochlear nerve
     n : either of the two cranial nerves on either side that control
         the superior oblique muscles of the eyes [syn: {trochlear},
          {trochlearis}, {fourth cranial nerve}]