anvil cloud

anvil cloud

n.

The upper portion of a well-developed cumulonimbus cloud that has reached an altitude at which high lateral winds blow across the top of the cloud, creating a flat anvil shape.

American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

anvil cloud

or

anviltop

n

another name for a cumulonimbus cloud, which tends to be anvil-shaped

Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014