fit in with fit in with {v. phr.} To fall into agreement or accord with. His plans to take a vacation in early July fit in perfectly with the university schedule. Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: F Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Leave my opinion