pluvial

In the early 17th century, clerics began wearing long cloaks known as "pluvials" for protection against the rain during processions. The name of the cloak is based on the Latin word for "rain": "pluvia." By the mid-17th century, "pluvial" was also being used as an adjective meaning "of or relating to rain," as in "pluvial water." Later, in the 19th century, it made a splash in the geologic field as a word describing epochs having relatively high average rainfall and things caused or formed by rain, like "pluvial erosion" or "pluvial lakes."