- extra help or support that you can get if necessary
- The police had backup from the army.
- We can use him as a backup if one of the other players drops out.
- The hospital has a backup power supply.
Definitions on the go
Look up any word in the dictionary offline, anytime, anywhere with the Oxford Advanced Learner’s Dictionary app.
- (computing) a copy of a file, etc. that can be used if the original is lost or damaged
- Always make a backup of your work.
- a backup copy
Check pronunciation:
backup