single-fish noun a urination UK:SCOTLAND Glasgow rhyming slang for PISHPISS
Ah’m away fur a single fish. — Michael Munro, ThePatter,AnotherBlast, 1988
Drivers opted to hold it in rather than risk being propositioned, murdered or arrested if they stopped for a quick single-fish. — Christopher Brookmyer, BoilingaFrog, p. 297, 2000