rest assured rest assured {v. phr.} To be convinced; persuaded; certain and unworried. "Please rest assured," he said seriously, "that I will keep all of my promises." Categories: add yours {v. phr.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: R Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Leave my opinion