side with . side with {v.} To agree with; help. Alan always sides with Johnny in an argument. Gerald sided with the plan to move the club. Contrast: SIDE AGAINST. Categories: add yours {v.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: S Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Add my comment