动词 double up:

1. bend over or curl up, usually with laughter or pain

2. share a room or a bed designed for only one person

3. stake winnings from one bet on a subsequent wager

Doubledayn.道布尔迪doubleadj.双重的；成双的；两倍的v.翻一番；使 ... 加倍n.两倍；双份double strands双链, 双线, 双股Double J stent双J管double-throw双掷,双投double ceiling双层天花double inertia双惯性环节double pyramid对顶棱锥double complex二重复形double parting错车道double fractal双分形double-dioden.双散热片二极管

1. The old couple doubled up with laughter.
   老两口笑得直不起腰来。
2. He doubled up when he was struck in the belly.
   他的肚子被击中时，他痛得蹲了下来。
3. They have to doubled up.
   他们只得同住一屋。
4. He doubled up in pain.
   他疼得弯下了腰。