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Definition of backup
(Entry 1 of 2)
1a : one that serves as a substitute or support
I brought an extra pencil for backup. a backup plan
b : musical accompaniment
The tunes include banjo and guitar backup.
c : additional personnel who provide assistance
The police officer called for backup.
2 : an accumulation caused by a stoppage in the flow
traffic backup
3 : a copy of computer data (such as a file or the contents of a hard drive)
I made a backup copy of the file. also : the act or an instance of making a backup
back up
verbbacked up; backing up; backing up
Definition of back up (Entry 2 of 2)
: to accumulate in a congested state
traffic backed up for miles
1 : to move into a position behind (a teammate) in order to assist on a play
3 : to make a copy of (a computer file or data) to protect against accidental loss or corruption
Be sure to back up your work. also : to make copies of all the files on (a device) a program that automatically backs up your hard drive
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Time Traveler for backup
The first known use of backup was in 1801
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