A cloud is a clump of water vapor that you can see in the sky. Clouds are sometimes white and puffy, and other times so big and gray that they completely block the sun.

Clouds form when air rises and cools and the moisture in it condenses into a visible form. Any similar billowy mass is also a cloud, like a cloud of smoke over your campfire or a cloud of dust after your car peels out of the driveway. If you're gloomy or morose, someone might say there's a cloud over you — a figurative cloud of sadness. On the other hand, if you're "on cloud nine," you couldn't be happier.

Primary Meanings of cloud

a visible mass of water or ice particles suspended at a considerable altitude
make overcast or cloudy
out of touch with reality
a cause of worry or gloom or trouble
make gloomy or depressed
Full Definitions of cloud

n a visible mass of water or ice particles suspended at a considerable altitude

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cirrocumulus, cirrocumulus cloud
a cloud at a high altitude consisting of a series of regularly arranged small clouds resembling ripples
cirrostratus, cirrostratus cloud
a thin uniform layer of hazy cloud at high altitude
cirrus, cirrus cloud
a wispy white cloud (usually of fine ice crystals) at a high altitude (4 to 8 miles)
cloud bank
a layer of clouds seen from a distance
condensation trail, contrail
an artificial cloud created by an aircraft; caused either by condensation due to the reduction in air pressure above the wing surface or by water vapor in the engine exhaust
cumulonimbus, cumulonimbus cloud, thundercloud
a dark cloud of great vertical extent charged with electricity; associated with thunderstorms
cumulus, cumulus cloud
a globular cloud
mother-of-pearl cloud, nacreous cloud
a luminous iridescent cloud at a high altitude that may be seen when the sun is a few degrees below the horizon
a small cloud
nimbus, nimbus cloud, rain cloud
a dark grey cloud bearing rain
storm cloud
a heavy dark cloud presaging rain or a storm
stratus, stratus cloud
a large dark low cloud
altocumulus, altocumulus cloud
a cumulus cloud at an intermediate altitude of 2 or 3 miles
altostratus, altostratus cloud
a stratus cloud at an intermediate altitude of 2 or 3 miles
mare's tail
a long narrow flowing cirrus cloud
a rounded projecting mass of a cumulus cloud with shining edges; often appears before a thunderstorm
Type of:
atmospheric phenomenon
a physical phenomenon associated with the atmosphere

n any collection of particles (e.g., smoke or dust) or gases that is visible

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(astronomy) the luminous cloud of particles surrounding the frozen nucleus of a comet; forms as the comet approaches the sun and is warmed
an immense cloud of gas (mainly hydrogen) and dust in interstellar space
a cloud of solid or liquid particles in a gas
cosmic dust
clouds of particles or gases occurring throughout interstellar space
dust cloud
a cloud of dust suspended in the air
mushroom, mushroom cloud, mushroom-shaped cloud
a large cloud of rubble and dust shaped like a mushroom and rising into the sky after an explosion (especially of a nuclear bomb)
diffuse nebula, gaseous nebula
a cluster of stars within an intricate cloud of gas and dust
planetary nebula
a nebula that was once thought to be a star with its planets but is now thought to be a very hot star surrounded by an expanding envelope of ionized gases that emit a fluorescent glow because of intense radiation from the star
droplets of water vapor suspended in the air near the ground
atmospheric moisture or dust or smoke that causes reduced visibility
fume, smoke
a cloud of fine particles suspended in a gas
Type of:
physical phenomenon
a natural phenomenon involving the physical properties of matter and energy

n a group of many things in the air or on the ground

clouds of blossoms”
“it discharged a cloud of spores”
infestation, plague
a swarm of insects that attack plants
Type of:
group, grouping
any number of entities (members) considered as a unit

v make overcast or cloudy

brighten, clear, clear up, light up
become clear
fog up
get foggy
become hazy, dull, or cloudy
Type of:
make dark or darker

v make milky or dull

“The chemical clouded the liquid to which it was added”
Type of:
make less lively or vigorous

v billow up in the form of a cloud

“The smoke clouded above the houses”
Type of:
billow, wallow
rise up as if in waves

v make less visible or unclear

“The stars are obscured by the clouds
becloud, befog, fog, haze over, mist, obnubilate, obscure
cast a shadow upon
eclipse, occult
cause an eclipse of (a celestial body) by intervention
Type of:
conceal, hide
prevent from being seen or discovered

v make less clear

“the stroke clouded memories of her youth”
Type of:
alter, change, modify
cause to change; make different; cause a transformation

v color with streaks or blotches of different shades

dapple, mottle
variegate with spots or marks
speckle, stipple
produce a mottled effect
Type of:
mark with a spot or spots so as to allow easy recognition

n out of touch with reality

“his head was in the clouds
Type of:
irreality, unreality
the state of being insubstantial or imaginary; not existing objectively or in fact

n a cause of worry or gloom or trouble

“the only cloud on the horizon was the possibility of dissent by the French”
Type of:
gloom, gloominess, glumness
an atmosphere of depression and melancholy

n suspicion affecting your reputation

“after that mistake he was under a cloud
Type of:
the state of being suspected

v make gloomy or depressed

“Their faces were clouded with sadness”
Type of:
affect, impress, move, strike
have an emotional or cognitive impact upon

v place under suspicion or cast doubt upon

corrupt, defile, sully, taint
Type of:
deflower, impair, mar, spoil, vitiate
make imperfect

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