brown Share definition Flag United Kingdom slang for a cigarette. Another slang word is 'fag', and the cockney rhyming slang 'fag' goes to brown bag, which is shortened to brown. Shall we duck for a brown? I brownsed so much last night. 'Low it, I've only got 2 browns left. Beg you buy a 20 deck. brown by brownser May 11, 2007 Get the brown mug.