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slang The act of urinating. The phrase comes from rhyming slang in which "Jimmy Riddle" rhymes with "piddle" (a slang term for "urinate"). Primarily heard in UK. Those three cups of coffee are catching up with me. Be right back, I'm off to have a Jimmy Riddle.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.