They're called stratus clouds
A dark rain cloud is called a nimbus. These clouds produce rain and snow as they are filled with compact and frozen moisture.
Cumulonimbus clouds are what heaps of rain clouds are called. Vertical clouds are the heaped up ones, so their names include the root " cumulus." The big, towering storm clouds are called cumulonimbus.
In Old English clouds used to be called weolcan, but the word for a rock was clod, like a clod of earth. Clouds were the same sort of shape as rocks, so they were gradually called clods, and then clouds. So it was the Anglo Saxons, or Old English, who lived between the 5th and the 11th Centuries, who first called clouds clouds.
cumulonimbus clouds
It is called secondary structure of proteins .
Large groups of galaxy clusters that appear in sheetlike and threadlike shapes are called superclusters.
skin
intramembranous bones
aponeurosis
They are called "cumulus" clouds, and sometimes are colloquially called "fair weather" clouds.