in reason . in reason {adv. phr.}, {formal} Following the rules of reasoning; sensibly; reasonably. One cannot in reason doubt that freedom is better than slavery. Categories: add yours doubt {adv. phr.} {formal} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2024 To section: I Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Add my comment