Overhead :: Overhead (adv.) Aloft; above; in or attached to the ceiling or roof; in the story or upon the floor above; in the zenith.
Overhear :: Overhear (v. t.) To hear more of (anything) than was intended to be heard; to hear by accident or artifice.
Overheat :: Overheat (v. t.) To heat to excess; to superheat.