If you are refering to popular lines like "Disappearing in a cloud of dust" or "in a cloud of smoke" it can be refering to a cleche' as in old westernes when cowboys would ride of into the sunset, the hooves of their horses kicking up a cloud of dust and in that way he would "disappear" from sight. In the same way, magicians used to set smoke off on stage to help in their disappearing acts to blind the audience from not seeing exactly what they were doing.
I hope this answeres your question ;D
a dust cloud
marshmallow
Yes, "I wandered lonely as a cloud" is a metaphor. It compares the speaker's experience of solitude to that of a cloud floating aimlessly in the sky.
A nebula.
My bed is LIKE a cloud. A metaphor would be "My bed IS a cloud"
A Cloud of Red Dust was created on 1997-10-06.
on cloud nine
Example:the tree is a cloud
dust
A cloud of dust and gas in space is known as a Nebula.
A cloud of grain dust
simile because it is comparing the cloud with a lonely man.