tailback - Wiktionary, the free dictionary

From Wiktionary, the free dictionary

From tail +‎ back.

tailback (plural tailbacks)

1. (UK, Ireland, Commonwealth) A line of motor vehicles causing or the result of traffic congestion or a traffic jam.

   Synonym: backup (US)

   • 2013 August 14, Simon Jenkins, The Guardian‎^[1]:

     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.

2. (American football) A running back or halfback who lines up furthest to the rear in an I formation.