English Reference

Word

cloud

US/ˈkɫaʊd/

UK/klˈaʊd/

Definitions

01in the sky

A2 · Elementary Countable noun

n. a white or grey mass of water drops floating in the sky.

n. a visible mass of condensed water vapour or ice crystals suspended in the atmosphere.

“The sun disappeared behind a thick dark cloud just before the rain started.”

“Wispy cirrus clouds streaked the upper atmosphere, indicating a change in weather patterns as the cold front approached from the north.”

Synonyms

02computing

B1 · Intermediate Uncountable noun Computing

n. a way to store and use information on the internet instead of on your own computer.

n. a network of remote servers hosted on the internet to store, manage, and process data.

“I save all my photos to the cloud so I can see them on my phone.”

“The enterprise migrated its entire database to the cloud to ensure seamless accessibility for its global workforce.”

Usage

Usually used with the definite article: 'the cloud'.

Synonyms

online storageremote server

Antonyms

local storage

03a mass of something

B1 · Intermediate Countable noun

n. a large amount of dust, smoke, or insects moving together through the air.

n. a large, moving mass of particles or organisms suspended in the air.

“A cloud of dust rose from the road as the truck drove past.”

“The explosion sent a massive cloud of ash into the stratosphere, disrupting air travel across the continent for several days.”

Synonyms

swarmbillowhaze

04something negative

B2 · Upper Intermediate Countable noun

n. a feeling or situation that makes you feel sad or worried.

n. a state or cause of gloom, suspicion, or trouble hanging over a person or situation.

“The news of the factory closing cast a cloud over the whole town.”

“The scandal cast a persistent cloud over his political career, making it difficult for him to regain the public's trust.”

Synonyms

05to make unclear

B2 · Upper Intermediate

v. to make something difficult to see through or difficult to understand.

v. to make something obscure, confused, or less clear.

“Don't let your anger cloud your judgment when you make this decision.”

“The witness's testimony served only to cloud the issue further, introducing several contradictions that the jury found difficult to reconcile.”

Antonyms

06to become misty

B1 · Intermediate

v. to become covered with steam or mist so you cannot see through it.

v. to become opaque or obscured by moisture or a film.

“The bathroom mirror started to cloud over while I was taking a hot shower.”

“His glasses clouded up immediately as he stepped from the freezing winter air into the humid greenhouse.”

Usage

Often used with 'over' or 'up'.

Synonyms

mist overfog up

Real-World Examples

“This aims to coax clouds to produce more moisture using tiny particles, often silver iodide, which has a similar shape and weight to an ice particle.”
BBC 12 Feb 2026
“In the tropics, along the band of sky near the equator, clouds and wind run the show.”
The Atlantic 28 May 2024
“Clouds, however, naturally reflect the sun (it’s why Venus – a planet with permanent cloud cover – shines so brightly in our night sky).”
BBC 24 Feb 2022
“Cloud computing has been an information technology buzzword for many years.”
BBC 5 May 2010

Etymology

From Old English clūd, a word for rock, hill, or boulder — the sense of "mass" rather than "vapour". The term descends from Proto-West Germanic klūt and Proto-Germanic klūtaz, both denoting a lump or conglomeration, with cognates still visible in German Kloß (a dumpling), Danish klode (sphere, planet), and the Low German Kluut and Kluute.

The semantic shift from solid earth to skyborne water is recorded by the early fourteenth century, when English cloud began displacing the older wolken — itself the ancestor of Modern English welkin and the common Germanic root surviving in Dutch wolk and German Wolke. The older term had meant cloud in the meteorological sense; the newer one arrived from geology and took over by accident of sound change and fashion. The original sense survives only in compounds and fixed phrases, and in the related English words clod, clot, clump, and club — all descendants of the same Proto-Indo-European root gel-, meaning to ball up or clench.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Synonyms

Antonyms

Word family

NOUN

cloud(A2)

ADJECTIVE

Related words

Idioms

Domain

Computing

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.A2 KeyIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.3.0–4.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 2.0–2.524–43TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.225–549
Frequency
Common
Level
A2 · ElementaryOxford
Updated

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