do one good . do one good {v. phr.} To benefit. The fresh air will do you good after having been inside the house all day. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: D Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry