ethmoidal foramen

n.
  1. Either of two foramina, anterior and posterior, formed by grooves on either edge of the ethmoidal notch of the frontal bone and by similar grooves on the ethmoid bone.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.