cap cloud

noun

, Meteorology.

1. a stationary cloud directly above an isolated mountain peak. Compare banner cloud, crest cloud.
2. pileus ( def 3 ).

Word History and Origins

Origin of cap cloud¹

First recorded in 1860–65

Example Sentences

Thus, the cloud is present only over the top of the mountain and just downwind, forming a hat-like cap cloud that is often circular.

From Washington Post

Lovely little cap cloud over Rainier this afternoon.

From Seattle Times