Cusp may refer to: Cusp (singularity), a singular point of a curve Cusp form in modular form theory Cuspidal representation, a generalization of cusp forms in the theory of automorphic representations Cusp (dentistry), a pointed structure on a cuspid, premolar, or molar Cusps of heart valves, leaflets of a heart valve Cusp (astrology), a boundary between zodiac signs and houses Cusp (novel), a science fiction story by Robert A. Metzger… (More on Cusp)