The Collaborative International Dictionary
Mesethmoid
Mesethmoid \Mes*eth"moid\, a. [Mes- + ethmoid.] (Anat.) Of or pertaining to the middle of the ethmoid region or ethmoid bone. -- n. (Anat.) The median vertical plate, or median element, of the ethmoid bone.
Wiktionary
mesethmoid
n. (context anatomy English) A bony cartilage, in the centre of the ethmoid part of the skull, that makes up most of the nasal septum