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definitions

quadrate muscle of upper lip

n.
  1. A muscle composed of three heads usually described as three muscles: the elevator muscle of the upper lip and wing of the nose, the elevator muscle of the upper lip, and the lesser zygomatic muscle.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.