Usually hazard lights. an indicator light on a vehicle that flashes to warn that it is unexpectedly slowing down, reversing, or not moving.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the indicator lights of a motor vehicle when flashing simultaneously to indicate that the vehicle is stationary and temporarily obstructing the trafficAlso called: hazard warning lights, hazards
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012