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casting vote

American  

noun

  1. the deciding vote of the presiding officer of a deliberative body, made when the other votes are equally divided.

casting vote British  

noun

  1. the deciding vote used by the presiding officer of an assembly when votes cast on both sides are equal in number

"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 casting vote

First recorded in 1685–95

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.