n.

1. 【天】半影（日、月蝕或太陽黑子周圍的半暗部）
2. （繪畫）濃淡相交處
3. 曖昧的部分

n.

1. the partially shaded outer region of the shadow cast by an opaque object, especially the area of the earth or moon experiencing a partial eclipse.
2. Astronomy  the less dark outer part of a sunspot.