Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio.
noun pl. philtra
the vertical indentation between the upper lip and the nose
Used by arrangement with John Wiley & Sons, Inc.
philtrum - Medical Definition
The American Heritage® Medical Dictionary Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
noun pl. phil·tra
The vertical indentation in the midline of the upper lip. Also called infranasal depression.