- a broad membrane bone of the skull, forming the forehead and the upper portion of each orbit.
Origin of frontal bone
First recorded in 1735–45
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the bone forming the forehead and the upper parts of the orbits. It contains several air spaces
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
- A cranial bone consisting of a vertical portion corresponding to the forehead and a horizontal portion that forms the roofs of the orbital and nasal cavities.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.