double up

Verb

• To double the quantity, amount or duration of something
• To double one's amount of chips by winning an all-in pot.
• To bend, bend over; to fold; to stoop.
• To have a secondary use.
• 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
• To employ double the usual resources for a particular purpose.