back pay/rent/tax, etc. › pay, rent, tax, etc. that should have been paid or was expected at an earlier time: Most of the back taxes due were for the years 2006 through 2008.
on the back burner › If something is on the back burner, it is not being dealt with at the present time, especially because it is not urgent or important, but it will be dealt with in the future: Any plans of opening new restaurants are on the back burner until the recession ends. I lost my job and had to put my plans to move house on the back burner.
take a back seat › to become less important (than something else): Agriculture, which generates only about $50 million a year in revenue, takes a back seat to other industries like oil and gas that bring in billions of dollars. Environmental issues take a back seat in tough economic times. › to let other people have a more active and responsible position than you in an organization or activity: After appointing a new chief executive, the chairman of the fashion chain is finally taking a back seat at the business he founded.