a triangular protection from the intrados of an arch, or from an inner curve of tracery.-the beginning or first entrance of any house in the calculations of nativities, etc.-the point or horn of the crescent moon or other crescent-shaped luminary.-a multiple point of a curve at which two or more branches of the curve have a common tangent.-a prominence or point, especially on the crown of a tooth.-a sharp and rigid point.-to furnish with a cusp or cusps.