A condition of low priority; in a cooking phrase, it usually follows "on the..."
1945-
50; from the custom in cooking of placing pots not requiring immediate attention 
toward the... [DOC] [TLE] Back-burner | Define Back-burner at Dictionary.com [PAR] Follow @dictionarycom ... 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.