sight unseen sight unseen {adv. phr.} Before seeing it; before seeing her, him, or them. Tom read an ad about a car and sent the money for it sight unseen. Categories: add yours {adv. phr.} 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 Leave my opinion