taillight . taillight {n.} The rear red light of a car. My father was fined $15 for driving without a taillight. Categories: add yours add yours {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: T Subscribe to: American Idioms► Also consider the parent subscriptions (3)Idioms feedEnglish languageHome page and general feed Add my comment Add my comment