double up

/ˈdʌb.əl ʌp/ 动词

To double the quantity, amount or duration of something. (transitive) · I'm going to double up my enlistment.
To double one's number of chips, especially in poker by winning an all-in pot. (intransitive)
To bend, bend over; to fold; to stoop. (intransitive) · Near-synonym: double over
To cause (someone) to bend over; to beat up (someone). (transitive) · I doubled him up with a swift punch to the stomach.
To have a secondary use. (intransitive) · This unfolding sofa doubles up as a bed.
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 (transitive) · Jones snared the liner and then stepped on the bag to double up the runner.
To employ double the usual resources for a particular purpose; to work in pairs. (intransitive)
To marry or live with someone; to share a living space. (intransitive, slang)

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