by mistake . by mistake {adv. phr.} As the result of a mistake; through error. He picked up the wrong hat by mistake. Categories: add yours {adv. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 » In RussianTo section: B Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Discuss