cusp

詳細解釋：

cusp

n.（名詞）
A point or pointed end.
頂點，尖端
Anatomy
【解剖學】
A pointed or rounded projection on the chewing surface of a tooth.
牙尖：牙齒咬合面上的尖狀或圓形凸起
A triangular fold or flap of a heart valve.
尖瓣：心臟瓣膜的褶皺或瓣片之一
Mathematics A point at which a curve crosses itself and at which the two tangents to the curve coincide.
【數學】 尖點，會切點：曲線上的一個點，曲線在該點與其本身相交，曲線的兩條切線在該點重合
Architecture The point of intersection of two ornamental arcs or curves, such as the inner points of a trefoil.
【建築學】 尖頂：兩條裝飾性弧線或曲線的交叉點，如三葉飾的內尖頂
Astronomy Either point of a crescent moon.
【天文學】 月角：新月的任一月尖
A transitional point or time, as between two astrological signs.
過渡：過渡點或過渡時間，尤指占星術的兩個天宮之間的

來源：
Latin cuspis [point]
拉丁語 cuspis [尖端]