depressor muscle of angle of mouth

n.
  1. A muscle with origin from the lower border of the mandible, with insertion near the angle of the mouth, with nerve supply from the facial nerve, and whose action pulls down the corners of the mouth.triangular muscle
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.