tailback

plural tailbacks

1. CommonwealthIrelandUKA line of motor vehicles causing or the result of traffic congestion or a traffic jam.

   1 more example

   The idea of a British warship supposedly menacing Spain is ludicrous. Is it meant to bomb Cadiz? Will its guns lift a rush-hour tailback in a colony that most Britons regard as awash with tax dodgers, drug dealers and right-wing whingers? The Gibraltarians have rights, but why British taxpayers should send warships to enforce them, even if just "on exercise", is a mystery.

   2013 August 14, Simon Jenkins, The Guardian

   Synonyms: backup

2. American footballA running back or halfback who lines up furthest to the rear in an I formation.