Cloud, Clouds.
He is in the clouds. In dreamland, entertaining visionary notions; having no distinct idea about the matter in question.
He is under a cloud. Under suspicion, in disrepute.
To blow a cloud is to smoke a cigar or pipe.
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Entry taken from Dictionary of Phrase and Fable, edited by the Rev. E. Cobham Brewer, LL.D. and revised in 1895.