cloud _noun

1-) a white or grey mass of water vapour in the sky

ADJECTIVES & NOUNS

dark, grey, black 
・Dark clouds usually mean rain.

white
・There was a bright blue sky with a few white clouds.

heavy, thick 
・By midday, heavy cloud had spread across the sky.

low, high 
・Low cloud spoiled our view from the top of the hills.

storm, rain
・Dark storm clouds were moving in from the Atlantic.

threatening
・By ten o’clock the threatening clouds had vanished and the town was bathed in sunlight.

thunder (also thundercloud)
・He pointed to the black thunderclouds overhead.

CLOUD + NOUN
cover
・The cloud cover should disappear by the afternoon. 

formation 
・His notebooks contain careful descriptions of cloud formations.

VERBS

gather, form 
・The sky had darkened and clouds had gathered.

cover, hide, obscure
・The moon was now hidden by clouds and the sky was dark.

clear, lift
・At last the rain had stopped and the clouds had cleared.

part 
・Suddenly the clouds that covered the moon parted.

move, roll 
・A narrow band of cloud has been moving across the country.

drift, float
・A few clouds drifted across the top of the mountains.

race, scud
・A strong wind was blowing and the clouds were scudding across the sky.

hang above/over 
・Heavy grey clouds hung over the town.

PHRASES

a bank/mass of cloud 
・A heavy bank of cloud was creeping across the sky.

a band of cloud 
・Long narrow bands of cloud stretched across the valley.

a layer of cloud
・The moon was shining through a thin layer of cloud.

a blanket/veil of cloud 
・In the morning, a blanket of cloud still covered the hills.

wisps of cloud
・The plane flew through occasional wisps of cloud.

a break/gap in the cloud(s)
・The moon was visible through breaks in the cloud.

the sun breaks through the clouds 
・The late morning sun was beginning to break through the clouds.

2-) a mass of dust, smoke, etc. in the air

ADJECTIVES & NOUNS

great, big, huge, vast 
・Where the bomb had landed, there was a great cloud of dust.

thick, dense
・These volcanic eruptions throw up dense clouds of ash.

swirling 
・A swirling cloud of smoke hid everything.

billowing 
・Another piece of wall collapsed, sending up a billowing cloud of dust.

VERBS

rise
・When I turned over, a big cloud of dust rose from the mattress.

PHRASES

a cloud of dust/ash, a dust/ash cloud
・The car disappeared down the road in a cloud of white dust.
・The plane flew into a volcanic ash cloud.

a cloud of smoke/steam/gas
・The fire sent up a huge cloud of smoke.