in error . in error {adv. phr.} Wrong; mistaken. You were in error when you assumed that he would wait for us. Categories: add yours add yours {adv. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: I Subscribe to: American Idioms► Also consider the parent subscriptions (3)Idioms feedEnglish languageHome page and general feed Post my comment Post my comment