back up
(to support someone)
- I’ll back you up throughout the court case.
(to prove that what someone is saying is true)
- Recent study backs up her claims.
(to make a copy of computer information)
- Make sure you back up your files every day.
(to move backward)
- I need everyone to back up a little.
(to form a line due to congestion)
- Traffic backed up for miles on the road to the coast.