‖Troch″le‐a (?), n. [L., a case or sheaf containing one or more pulleys, Gr. �. See Trochilics.] 1. (Mach.) A pulley.
2. (Anat.) A pulley, or a structure resembling a pulley; as, the trochlea, or pulleylike end, of the humerus, which articulates with the ulna; or the trochlea, or fibrous ring, in the upper part of the orbit, through which the superior oblique, or trochlear, muscle of the eye passes.