- noun a ridge or projection on the grinding surface of a molar tooth
- noun a flap or fold of tissue that forms part of a valve in the heart, veins or lymph vessels
- noun the point where two arcs of a curve meet
- Angular horn-like point on the visible, lit face of the Moon, or of Mercury or Venus. They are also seen on space probe photographs of the other major planets, but not from Earth because the other planets are seen virtually fully lit by observers on the Earth.