the fully shaded inner region of a shadow cast by an opaque object, especially the area on the earth or moon experiencing the total phase of an eclipse 暗影;本影。 比较penumbra ■(Astronomy)the dark central part of a sunspot (天文)太阳黑子中心 ■[mass noun](chiefly poetic/literary)shadow or darkness (主诗/文)荫,阴影
派生 umbral adjective 语源
late 16th cent. (denoting a phantom or ghost): from Latin, literally shade'