from The American Heritage® Dictionary of the English Language, 5th Edition.

  • noun A dense, white, fluffy, flat-based cloud with a multiple rounded top and a well-defined outline, usually formed by the ascent of thermally unstable air masses.
  • noun A pile, mound, or heap.

from The Century Dictionary.

  • noun The kind of cloud which appears in the form of rounded heaps or hills, snowy-white at top with a darker horizontal base, characteristic of mild, calm weather, especially in summer; the summer-day cloud. See cut under cloud, 1.
  • noun In anatomy, a heap of cells surrounding a ripe ovum in the Graafian follicle, and constituting the discus proligerus.

from the GNU version of the Collaborative International Dictionary of English.

  • noun (Meteor.) One of the four principal forms of clouds. Seecloud.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

  • noun A large white puffy cloud that develops through convection. On a hot, humid day, they can form towers and even become cumulonimbus clouds.
  • noun A mound or heap.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • noun a collection of objects laid on top of each other
  • noun a globular cloud


from The American Heritage® Dictionary of the English Language, 4th Edition

[Latin, heap; see keuə- in Indo-European roots.]


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  • The word cumulus has a root similar to accumulate and means “piled up.”

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  • The first stage of air mass thunderstorm development is called the cumulus stage (Figure 3).


  • This works to loosen a gel-like coating and sticky layer of cells known as the cumulus corona.

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  • Go out and explain me one of those great wads of wool called cumulus or cumulonimbus.

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  • The ships are given the names of clouds, such as "cumulus" and "mares tails" which the protagonist of the story, Master Tem, has an ability to predict their patterns and severity in order to warn the townspeople of possible floods and other storms brought on by them.

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  • Jonker said it was unclear, for example, whether there would be more or fewer low clouds, such as cumulus clouds, in warmer conditions, which would affect the rate of global warming because of their role in reflecting sunlight away from the earth.

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  • The researchers focused their lab studies on the lower 'fair-weather' clouds such as cumulus, which reflect sunlight away from the earth and therefore have a cooling effect.

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  • When lower and in heavy roundish masses it's called alto-cumulus, which is the fifth on the list, and when it is lower still and looks like a lot of great blue-gray footballs wedged closely together it is known as strato-cumulus. "

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  • "cumulus" cloud; and in a few seconds afterwards, huge fragments of the wreck showered down, far and wide, upon the river and the adjacent shore.

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  • A young, crisp cumulus can develop a "pileus"—a delicate, evanescent cloud-cap, which Mr. Pretor- Pinney disconcertingly likens to Donald Trump's comb-over.

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  • Citation on pus.

    June 22, 2008