a grey or white mass in the sky, made up of very small floating drops of water:
rain cloud Do you think those are rain clouds on the horizon?
The sky was a perfect blue - not a cloud in sight.
Dark clouds massed on the horizon.
UK There was so much cloud, we couldn't see anything.
a mass of something such as dust or smoke that looks like a cloud:
cloud of On the eastern horizon, a huge cloud of smoke from burning oil tanks stretched across the sky.
The initial cloud of tear gas had hardly cleared before shots were fired.
If something transparent clouds, or if something clouds it, it becomes difficult to see through.
to make someone confused, or make something more difficult to understand:
cloud someone's memory When it came to explaining the lipstick on his collar, he found that drink had clouded (= confused) his memory.
a white or gray mass of very small drops of water or ice that float in the sky:
[ C ] Those dark clouds look like we’re going to get some rain.
A cloud is also a mass of something, such as dust or smoke, that moves together:
The distant cloud of dust in the valley announced the approach of a car.
A cloud is also something which causes sadness or fear:
[ C ] After the diagnosis of cancer, she lived under a cloud.
to fill with clouds or with something that looks like a cloud:
[ T ] Smoke clouded the sky.
If something clouds a situation or feeling, it makes it less clear:
The fact that Jack was an old friend clouded her judgment.