double up (on something/with somebody) (informal) to form a pair in order to do something or to share something We'll have to double up on books; there aren't enough to go around. They only have one room left: you'll have to double up with Peter.

to share something, especially a room, with someone else: Terry will have to double up with Bill in the front bedroom. to receive or use two of something: Matt Damon doubled up, winning two Oscars that night.