arcus

[ahr-kuh s]

noun, plural ar·cus. Meteorology.

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

Origin of arcus

< Latin: bow, arch

Also called roll cloud.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for arcus

Historical Examples of arcus

A view of this is given by Donati, who calls it the Arcus Domitiani.
Old Rome
Robert Burn
Moreover, there is the arcus senilis, the fine translucent to opaque circle surrounding the outer portion of the iris.
Arteriosclerosis and Hypertension:
Louis Marshall Warfield
The Romans originally called their triumphal arch fornix, not arcus.
Rambles in Rome
S. Russell Forbes
Otia si tollas, periere Cupidinis arcus—Remove 45 the temptations of idleness, and Cupid's bow is useless.
Dictionary of Quotations from Ancient and Modern, English and Foreign Sources
James Wood
The frustules are curved or arcuate (arcus, a bow) in the side view, oblong and narrowed at the ends in the front view.
An Elementary Text-book of the Microscope
John William Griffith

arcus in Medicine

arcus

[är′kəs]

n. pl. arcus

A structure resembling a bent bow or an arch.

The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.