gin mill gin mill {n.}, {slang} A bar where liquor is sold. Rush Street in Chicago is full of gin mills. Syn.: SPEAKEASY. Categories: add yours {n.} {slang} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: G Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry