What does cloud mean?
A cloud is a visible collection of tiny water droplets or ice crystals suspended in the air, formed when moist air cools and condenses. Beyond weather, the word extends to almost any drifting, billowing mass — smoke from a fire, dust kicked up on a road, a swarm of insects — and, figuratively, to anything that darkens mood or reputation, as when suspicion hangs over a person like a cloud. In modern life it also names the vast network of remote servers we call 'the cloud', where photos, files, and software live beyond our own devices. The word's history is surprising: it originally meant a lump or mass of earth or rock, and only later came to describe the puffy masses overhead, likely because they resembled such heaps. Few everyday words are so versatile, moving effortlessly between meteorology, emotion, idiom, and technology.
A visible mass of water droplets or ice crystals suspended in the atmosphere.
"Dark clouds rolled in from the west just as we set up camp."
A hazy or billowing mass of something other than water vapour, such as smoke, dust, or steam.
"A great cloud of dust rose behind the departing truck."
To cover, darken, or obscure something, literally or figuratively.
"Tears clouded her vision as she read the letter."
Also used reflexively or passively: judgement can be 'clouded' by emotion.
(Of the face or expression) to become dull, troubled, or less bright.
"His brow clouded when he heard the news."
Regular plural. Often used uncountably in general statements about weather ('there were clouds all day').
"Wisps of clouds drifted across an otherwise clear sky."
Before the Middle Ages, 'cloud' didn't mean a puff in the sky at all — it meant a lump of rock or earth, which is why its cousins include clod and clot.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cloud
Old English 'clūd' meant a mass of rock or earth — essentially what we'd now call a clod. During the Middle English period the word shifted to describe visible masses of vapour in the sky, presumably by analogy with lumps of matter. It replaced the older native term 'welkin'-related vocabulary for the sky and pushed out Old English 'wolcen'. Its Germanic relatives include Dutch 'kluit' and German 'Klote/Kloß' (lump), and it ultimately traces to a Proto-Germanic root meaning a compacted mass.
Related word forms
How cloud is actually used
Register is neutral across all senses. The computing sense is a late-20th/early-21st-century development and is always used with 'the' ('the cloud'). Figurative uses tend toward negative connotations of gloom or doubt.
Easily confused with cloud
A clout is a heavy blow or influence (or an old word for a cloth patch), whereas a cloud is a visible mass in the sky — the words share ancient Germanic roots but mean entirely different things.