medicornu /ˌmiːdiˈkɔː(ɹ)njuː/ noun1 •The middle or inferior horn of each lateral ventricle of the brain.In man there are three extensions of the cella: cephalic, PRECORNU, ventral, MEDICORNU, and caudal, POSTCORNU; the last is wanting in the sheep as in most other mammals. — 1893 formsmedicornua