trochlear nerve n 1: either of the two cranial nerves on either side that control the superior oblique muscles of the eyes [syn: {trochlear}, {trochlear nerve}, {trochlearis}, {fourth cranial nerve}]
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. [1913 Webster] {Trochlear nerve}. See {Pathetic nerve}, under {Pathetic}. [1913 Webster]