Double up

I'm going to double up my enlistment.

Near-synonym: double over

'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![…]'

If I could jump high enough out of the water to wedge my doubled-up fist in that crack I could hang by it. If I opened my hand I'd slide right back in the water, but if I could keep my fist closed […]

I doubled him up with a swift punch to the stomach.

This unfolding sofa doubles up as a bed.

A little fearfully now, Pollyanna felt her way to these bags, selected a nice fat soft one (it contained Miss Polly's sealskin coat) for a bed; and a thinner one to be doubled up for a pillow, and still another (which was so thin it seemed almost empty) for a covering.

Fikayo Tomori, the Chelsea defender, sang “championes, championes” with his winners’ medal swaying from side to side. For Joshua Onomah and Ainsley Maitland-Niles, England banners doubled up as celebratory bandanas.

Jones snared the liner and then stepped on the bag to double up the runner.

Tactically smart, Leeds' work-rate was also admirable, their players often doubling up on Everton's main threats like Marouane Fellaini, while Victor Anichibe found he had unwelcome, unstinting company throughout.