external obturator muscle

n.
  1. A muscle with origin from the margin of the obturator foramen and the adjacent surface of the obturator membrane, with insertion into fossa of the greater trochanter, with nerve supply from the obturator nerve, and whose action rotates the thigh laterally.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.