middle cerebellar peduncle

n.
  1. The largest of the three paired peduncles, composed mainly of fibers that originate from the pontine nuclei, cross the midline in the basilar part of the pons, and emerge on the opposite side as a massive bundle arching dorsally along the lateral side of the pontine tegmentum into the cerebellum.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.