1.Definition: (computer science) 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"

Category: Objects

2.Definition: a musical part (vocal or instrumental) that supports or provides background for other musical parts

Related Noun(s):accompaniment, support

Category: General

3.Definition: an accumulation caused by clogging or a stoppage

"A traffic backup on the main street", "He discovered a backup in the toilet"

Category: General

4.Definition: someone who takes the place of another (as when things get dangerous or difficult)

Related Noun(s):relief, reliever, substitute

Category: People

5.Definition: the act of providing approval and support

Related Noun(s):championship, patronage

Category: General