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1. Point formed by two intersecting arcs (as from the intrados of a Gothic arch)
    
2. A thin triangular flap of a heart valve
   - leaflet
    
3. Small elevation on the grinding surface of a tooth
    
4. An event marking a unique or important historical change of course or one on which important developments depend
   - landmark, turning point, watershed
    
5. A sharp point or pointed end; a point where an otherwise smooth curve comes to a point

Derived forms: cusps

Type of: flap, juncture, occasion, peak, point, tip

Part of: cardiac valve, chopper [informal], heart valve, pearly [informal], tooth

Encyclopedia: Cusp