- 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 stand-in for dangerous scenes" "we need extra employees for summer fill-ins"
- a musical part (vocal or instrumental) that supports or provides background for other musical parts
- (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"
- the act of providing approval and support;
"his vigorous backing of the conservatives got him in trouble with progressives"
