Cūsp, n.

n. [Lat. cuspis, point, pointed end.] 1. (Arch.) A projecting point in the foliation or other ornamentation of arches, panels, &c.; also, a pendant of a pointed arch. “Two cusps form a trefoil; three, a quaterfoil.” Gwilt. 2. (Astrol.) The beginning or first entrance of any house in the calculations of nativities, &c. 3. (Astron.) The point or horn of the crescent moon or other crescent-shaped luminary. 4. (Math.) The point at which two curves, or two branches of the same curve, meet. Math. Dict. 5. (Zool.) The prominence on the molar teeth. Dana.