cusp has definitions from the fields of anatomy,zoology
1
[ noun ] point formed by two intersecting arcs (as from the intrados of a Gothic arch)

Used in print

(Robert Heinlein, Stranger in a Strange Land....)

Their meditations were approaching a violent cusp that would shape Martian art for many millennia .

Related terms

point

2
[ noun ] (anatomy,zoology) a thin triangular flap of a heart valve

Synonyms

leaflet

Related terms

flap heart_valve

3
[ noun ] small elevation on the grinding surface of a tooth

Related terms

point tooth

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