altostratus[al′tō strāt′əs, -strat′-]
altostratus definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
the type of gray or bluish cloud found at intermediate altitudes and consisting of a thick, dense, extensive layer of ice crystals and water droplets: may cause light precipitation
Origin: alto- plush stratus
altostratus definition by American Heritage Dictionary
The American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
An extended cloud formation of bluish or gray sheets or layers.
Origin: Latin altus, high; see al-2 in Indo-European roots + stratus.
altostratus - Science Definition
A mid-altitude cloud that extends in flat, smooth sheets or layers of varying thickness. Altostratus clouds generally form between 2,000 and 6,100 m (6,560 and 20,000 ft) and often produce long, steady rain showers. See illustration at cloud.