剑桥词典a type of cumulus (= a tall , rounded , white cloud with a flat base ) formed in a very thin layer and often in a regular pattern 卷積雲（一種稀薄的高空雲，由一系列槼則排列的白雲堆積形成,底部扁平） 比較altocumulus stratocumulus 返回 cirrocumulus