cumulus

noun

cu·​mu·​lus ˈkyü-myə-ləs 

plural cumuli ˈkyü-myə-ˌlī  -ˌlē 

1

: heap, accumulation

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

Synonyms of cumulus

• accumulation
• collection
• mixture
• assemblage
• jumble

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

Dean has an unerring sense about how to let her voice glide to the cumulus layer and back again, without remotely ever going over the top. — Chris Willman, Variety, 17 July 2026

Beehive is more delicate, sending up painterly tendrils that form a thin scrim in front of the landscape of volcanic sediment, evergreens, and puffy cumulus clouds. — Jesse Ashlock, Condé Nast Traveler, 14 July 2026

Throughout the morning, Lisius — and chasers who had fanned out across North Texas — waited for the drifting cumulus clouds to rise far enough to become a tornado-producing supercell thunderstorm. — Emily Holshouser may 19, Fort Worth Star-Telegram, 19 May 2026

Forecasters predict an 80 percent chance of favorable weather for launch Wednesday, with a low risk of cumulus clouds and ground winds that could violate NASA’s launch commit criteria. — Stephen Clark, ArsTechnica, 1 Apr. 2026

Word History

Etymology

Latin

First Known Use

1659, in the meaning defined at sense 1

Kids Definition

cumulus

noun

cu·​mu·​lus ˈkyü-myə-ləs 

plural cumuli -ˌlī 

-ˌlē

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

Medical Definition

cumulus

noun

cu·​mu·​lus ˈkyü-myə-ləs 

plural cumuli -ˌlī, -ˌlē 

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

called also discus proligerus