The Collaborative International Dictionary
Mesoseme
Mesoseme \Mes"o*seme\, a. [Meso- + Gr. ? sign, mark; cf. F. m['e]sos[`e]me.] (Anat.) Having a medium orbital index; having orbits neither broad nor narrow; between megaseme and microseme.
Wiktionary
mesoseme
a. (context anatomy English) Having a medium orbital index; having orbits neither broad nor narrow; between megaseme and microseme.