arcus

[ ahr-kuhs ]

noun

, Meteorology.

, plural ar·cus.

1. a dense, horizontal, roll-shaped cloud sometimes occurring at the lower front portion of a cumulonimbus.

Word History and Origins

Origin of arcus¹

< Latin: bow, arch

Example Sentences

Video shows a shelf cloud - a type of arcus cloud - form before a thunderstorm hit Portland.

From BBC

To Cassiopeia, she added, “Next time, try pluvius arcus, dear; the meaning is clearer.”

From Literature

In elderly persons we ought always to look for the arcus senilis, which is a sign of a tendency to fatty degeneration.

From Project Gutenberg

Moreover, there is the arcus senilis, the fine translucent to opaque circle surrounding the outer portion of the iris.

From Project Gutenberg

Because xanthelasmata are composed of foam cells similar to those present in atherosclerotic plaque, they may be a better marker than arcus corneae of the intra-arterial atherosclerotic process.”

From Forbes