nimbostratus

1610年代，“神圣人物周围的明亮云彩”，源自拉丁语 nimbus “云彩”，可能与 nebula “云、雾”有关（源自 PIE 词根 *nebh- “云”）。在艺术中，“神圣人物头部周围的光环”意义始于1727年。比较 aureole。

The nimbus of God the Father is represented as of triangular form, with rays diverging from it on all sides, or in the form of two superposed triangles, or in the same form (inscribed with the cross) as that of Christ. The nimbus of Christ contains a cross more or less enriched; that of the Virgin Mary is a plain circle, or occasionally a circlet of small stars, and that of angels and saints is often a circle of small rays. When the nimbus is depicted of a square form, it is supposed to indicate that the person was alive at the time of delineation. [Century Dictionary]

上帝之父的光环被描绘成三角形，其上发散着各种方向的光芒，或者是两个重叠的三角形形状，或者是与基督的形状相同（内刻十字架）。基督的光环包含一个或多个十字架； 圣母玛利亚的光环是一个简单的圆圈，或者偶尔是一圈小星星，而天使和圣徒的光环通常是一圈小光芒。当光环被描绘成正方形时，它被认为是表明这个人在描绘时还活着。[世纪词典]

"层云，" 1803年，源自拉丁语 stratus "扩散"，来自 sternere 的过去分词的名词用法，意为"展开，放下，伸展"，源自 PIE 词根 *stere- "展开"。