either horn of a crescent moon
a pointed projection formed by or arising from the intersection of two arcs, e.g. in Gothic tracery: compare foil1 (4a)
a pointed projection formed by or arising from the intersection of two arcs in Gothic tracery: compare foil1 (4a)
in mathematics, a point at which a curve is sharply reversed
a point on the grinding surface of a tooth
a fold or flap of a valve, in the heart or a blood vessel
the initial point of an astrological house
on the cusp
in transition between one state and another
cuspate /ʹkuspit, ʹkuspayt/ adj
[Latin cuspis point]