[ahr-kuh s]
noun, plural ar·cus. Meteorology.
  1. 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. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for arcus

Historical Examples of arcus

arcus in Medicine


n. pl. arcus
  1. 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.