double up

double up (third-person singular simple present doubles up, present participle doubling up, simple past and past participle doubled up)

1. (transitive) To double the quantity, amount or duration of something

   I'm going to double up my enlistment.

2. (poker, by extension, intransitive) To double one's amount of chips by winning an all-in pot.
3. (intransitive) To bend, bend over; to fold; to stoop.
   • 1886, Robert Louis Stevenson, Strange Case Of Dr Jekyll And Mr Hyde:

     "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!"

4. (intransitive) To have a secondary use.

   This unfolding sofa doubles up as a bed.

   • 2017 June 11, Ben Fisher, “England seal Under-20 World Cup glory as Dominic Calvert-Lewin strikes”, in the Guardian‎:

     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.

   • 1913 Eleanor Porter: Pollyanna: Chapter 7:

     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.

5. (baseball, transitive) To get the second out in a double play, typically referring to getting an out by beating a runner back to a base (often by throwing) after a fly ball has been caught

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

6. (intransitive) To employ double the usual resources for a particular purpose.
   • 2012, Ben Smith, Leeds United 2-1 Everton‎:

     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.