subscapular muscle

n.
  1. A muscle with origin from the subscapular fossa, with insertion into the humerus, with nerve supply from the upper and lower subscapular nerves from the fifth and sixth cervical nerves, and whose action rotates the arm medially.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.