noun, plural al·to·cu·mu·lus. Meteorology.
a cloud of a class characterized by globular masses or rolls in layers or patches, the individual elements being larger and darker than those of cirrocumulus and smaller than those of stratocumulus: of medium altitude, about 8000–20,000 feet (2450–6100 meters).
Origin of altocumulus
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
noun plural -li (-laɪ)
a globular cloud at an intermediate height of about 2400 to 6000 metres (8000 to 20 000 feet)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Plural altocumuli (ăl′tō-kyōōm′yə-lī′)
A mid-altitude cloud composed of fleecy white or gray patches or bands. Altocumulus clouds generally form between 2,000 and 6,100 m (6,560 and 20,000 ft). See illustration at cloud.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.