tailback noun definition in Motoring problems and accidents topic from the Oxford Advanced Learner's Dictionary

tailback

 noun: Motoring problems and accidents topic
[countable] (British English) a long line of traffic that is moving slowly or not moving at all, because something is blocking the road It took a couple of hours for the two-mile tailback to clear. There are five-mile tailbacks on the M25 this morning. There are reports of severe tailbacks in both directions.