ˌdouble ˈduty BrE AmE noun
do double duty to do more than one job or be useful for more than one thing at the same time
do double duty as
The sofa does double duty as a guest bed.
ˌdouble ˈduty BrE AmE noun
do double duty to do more than one job or be useful for more than one thing at the same time
do double duty as
The sofa does double duty as a guest bed.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012