Definition of Backup

Noun: backup 'bak,Ãºp

An accumulation caused by clogging or a stoppage
"a traffic backup on the main street"; "he discovered a backup in the toilet"
Someone who takes the place of another (as when things get dangerous or difficult)
"the star had a backup for dangerous scenes";
- stand-in, substitute, relief, reliever, backup man, fill-in
A musical part (vocal or instrumental) that supports or provides background for other musical parts
- accompaniment, musical accompaniment, support
(computing) a copy of a file or directory on a separate storage device
"he made a backup in case the original was accidentally damaged or erased";
- computer backup
The act of providing approval and support
"his vigorous backup of the conservatives got him in trouble with progressives";
- backing, championship, patronage

Verb: back up

Give moral or psychological support, aid, or courage to
- support
Move backwards from a certain position
"The bully had to back up";
- back off, back down
Establish as valid or genuine
"Can you back up your claims?";
- back
Make a copy of (a computer file) especially for storage in another place as a security copy
"You'd better back up these files!"
Become or cause to become obstructed
"The water pipe is backed up";
- clog, choke off, clog up, congest, choke, foul
Move backwards, esp. drive a vehicle backwards
- reverse