The Collaborative International Dictionary
Mesiad
Mesiad \Mes"i*ad\, adv. [Gr. me`sos middle + L. ad to.] (Anat.) Toward, or on the side toward, the mesial plane; mesially; -- opposed to laterad.
Wiktionary
mesiad
adv. (context anatomy English) Toward, or on the side toward, the mesial plane.