Jones snared the liner and then stepped on the bag to double up the runner.
It is well, then that we should be frank, said the other. We both think more than we have said; let us make a clean breast. This masked figure that you saw, did you recognise it? / Well, sir, it went so quick, and the creature was so doubled up, that I could hardly swear to that, was the answer. But if you mean, was it Mr. Hyde?--why, yes, I think it was!.
This unfolding sofa doubles up as a bed.
I'm going to double up my enlistment.