designating or of the perforated bone or bones that form part of the septum and walls of the nasal cavity: the olfactory nerves pass through the perforations
noun
an ethmoid bone
See ethmoid in American Heritage Dictionary 4
(ĕthˈmoidˌ) also eth·moi·dal(ĕth-moidˈl)
adjective
Of, relating to, or being a light spongy bone located between the orbits, forming part of the walls and septum of the superior nasal cavity, and containing numerous perforations for the passage of the fibers of the olfactory nerves.