cu·​mu·​lus | \ ˈkyü-myə-ləs How to pronounce cumulus (audio) \
plural cumuli\ ˈkyü-​myə-​ˌlī How to pronounce cumuli (audio) , -​ˌlē \

Definition of cumulus

2 [New Latin, from Latin] : a dense puffy cloud form having a flat base and rounded outlines often piled up like a mountain — see cloud illustration

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Examples of cumulus in a Sentence

the cumulus of sundry things that fill up one's attic and somehow sum up a lifetime of experiences
Recent Examples on the Web Pyrocumulus clouds are similar to the cumulus clouds people are used to seeing. Charles Jones, The Conversation, "Extreme wildfires can create their own dangerous weather, including fire tornadoes – here’s how," 25 Aug. 2020 The bubbly cumulus of the day will die off with the loss of heating. Ian Livingston, Washington Post, "PM Update: Seasonably warm into Thursday, with minimal humidity," 24 June 2020 His characters swoop over mountainous landscapes and arc through cerulean skies full of billowing white cumulus, leaving vapour trails twisting like ribbons in the air. The Economist, "Home Entertainment For Hayao Miyazaki, flight is a metaphor for freedom," 4 June 2020 Aragon says weather in central Florida on Saturday includes the potential presence of cumulus clouds and high winds. Artemis Moshtaghian And Jay Croft, CNN, "Weather postpones Atlas V rocket launch," 16 May 2020 In late afternoon, after a series of come-and-go light showers, a 2-mile-wide black cumulus formed over the top of the McCloud’s limestone ridge. Tom Stienstra,, "Fall at Shasta Lakes brings more wildlife than visitors," 21 Sep. 2019 The point is to smack you into spirituality, so that God can be perceived in a cumulus swirl or in the breathing of an infant (presumably West’s latest kid, Psalm, depicted in close-up, sleeping in his father’s arms). Spencer Kornhaber, The Atlantic, "Kanye West’s Austere Reform Church," 25 Oct. 2019 The Air Force 45th Space Wing on Wednesday gave the launch only a 30 percent chance of favorable weather conditions with primary concerns of cumulus clouds and lightning for Wednesday. Richard Tribou,, "Dropped from an airplane, Pegasus rocket to launch NASA’s ICON satellite into space," 9 Oct. 2019 Swollen, white and grey cumulus clouds served as the only warning of a potential threat. NBC News, "Some Floridians refuse to evacuate but worry about Hurricane Dorian's unclear trajectory," 31 Aug. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'cumulus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of cumulus

1659, in the meaning defined at sense 1

History and Etymology for cumulus


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Time Traveler for cumulus

Time Traveler

The first known use of cumulus was in 1659

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Statistics for cumulus

Last Updated

3 Sep 2020

Cite this Entry

“Cumulus.” Dictionary, Merriam-Webster, Accessed 29 Oct. 2020.

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More Definitions for cumulus


How to pronounce cumulus (audio)

English Language Learners Definition of cumulus

technical : a type of thick cloud that is rounded on top and has a flat base


cu·​mu·​lus | \ ˈkyü-myə-ləs How to pronounce cumulus (audio) \
plural cumuli\ -​ˌlī , -​ˌlē \

Kids Definition of cumulus

: a massive cloud form having a flat base and rounded outlines often piled up like a mountain


cu·​mu·​lus | \ ˈkyü-myə-ləs How to pronounce cumulus (audio) \
plural cumuli\ -​ˌlī, -​ˌlē How to pronounce cumuli (audio) \

Medical Definition of cumulus

: the projecting mass of granulosa cells that bears the developing ovum in a graafian follicle

called also discus proligerus

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