back up Meaning, Definition & Usage

1. verb give moral or psychological support, aid, or courage to
   support.
   
   • She supported him during the illness
   • Her children always backed her up
2. verb move backwards from a certain position
   back down; back off.
   
   • The bully had to back down
3. verb establish as valid or genuine
   back.
   
   • Can you back up your claims?
4. verb make a copy of (a computer file) especially for storage in another place as a security copy
   
   • You'd better back up these files!
5. verb become or cause to become obstructed
   clog; congest; choke; foul; clog up; choke off.
   
   • The leaves clog our drains in the Fall
   • The water pipe is backed up

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