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back burner

noun
  1. a condition of low priority or temporary deferment (usually used in the phrase on the back burner): Put other issues on the back burner until after the election.

Origin of back burner

First recorded in 1945–50; from the custom in cooking of placing pots not requiring immediate attention toward the rear of the stove
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for backburner

back burner

noun
  1. on the back burner put aside for the time being, as a subject that is not of immediate concern but that may be activated later; postponed
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