A Persian word meaning nonsense. It was popularised in 1824 by James Morier in his Adventures of Hajji Baba of Ispahan, a Persian romance. (Turkish, bosh lakerdi, silly talk.)
“I always like to read old Darwin's Loves of the Plants; bosh as it is in a scientific point of view.” —Kingsley: Two Years Ago (chap. x.).
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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