arcus

American  

[ahr-kuhs] / ˈɑr kəs /

noun

Meteorology.

plural

arcus

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

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Etymology

Origin of arcus

< Latin: bow, arch

Example Sentences

One evening, ominous, low-lying tube-shaped clouds known as arcus formed, and whitecaps appeared in the waves.

From The Wall Street Journal

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