dash light dash light {n.} A light on the front inside of a car or vehicle. Henry stopped the car and turned on the dash lights to read the road map. Categories: add yours {n.} Source: A Dictionary of American Idioms by A. Makkai, M.T. Boatner, J.E. Gates © 2025 To section: D Subscribe to: American IdiomsIdioms feedEnglish languageHome page and general feed Comment on this entry