The Collaborative International Dictionary
Megaseme
Megaseme \Meg"a*seme\, a. [Mega- + Gr. ? sing, mark: cf. F. m['e]gas[`e]me.] (Anat.) Having the orbital index relatively large; having the orbits narrow transversely; -- opposed to microseme.
Wiktionary
megaseme
a. (context anatomy English) Having the orbital index relatively large; having the orbits narrow transversely.