[duhb-uh l-doo-tee, -dyoo-]
designed to fill two functions: double-duty tools.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Fulfilling two functions at the same time, as in Our pickup truck does double duty, since it is used for the business and for family outings.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.