backup Meaning, Definition & Usage

1. noun an accumulation caused by clogging or a stoppage
   
   • a traffic backup on the main street
   • he discovered a backup in the toilet
2. noun someone who takes the place of another (as when things get dangerous or difficult)
   stand-in; fill-in; substitute; relief; reliever; backup man.
   
   • the star had a stand-in for dangerous scenes
   • we need extra employees for summer fill-ins
3. noun a musical part (vocal or instrumental) that supports or provides background for other musical parts
   support; accompaniment; musical accompaniment.
   
4. noun (computer science) a copy of a file or directory on a separate storage device
   computer backup.
   
   • he made a backup in case the original was accidentally damaged or erased
5. noun the act of providing approval and support
   backing; patronage; championship.
   
   • his vigorous backing of the conservatives got him in trouble with progressives

WordNet