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designated driver

American  
[des-ig-ney-tid drahy-ver] / ˈdɛs ɪgˌneɪ tɪd ˈdraɪ vər /

noun

  1. a person who abstains from alcoholic beverages at a gathering in order to be fit to drive companions home safely. DD

designated driver British  

noun

  1. a person who volunteers not to drink alcohol on a social occasion, so that he or she can safely drive other people who have been drinking

"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

Etymology

Origin of designated driver

First recorded in 1980–85

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.