back up

verb

1. give moral or psychological support, aid, or courage to

   verb.social

   Synonyms support

   Source: WordNet 3.0

2. move backwards from a certain position

   verb.motion

   Synonyms back down back off

   Source: WordNet 3.0

3. establish as valid or genuine

   verb.change

   Examples

   Can you back up your claims?

   Synonyms back

   Source: WordNet 3.0

4. make a copy of (a computer file) especially for storage in another place as a security copy

   verb.creation

   Examples

   You'd better back up these files!

   Source: WordNet 3.0

5. become or cause to become obstructed

   verb.contact

   Synonyms choke choke off clog clog up congest foul

   Antonyms unclog

   Source: WordNet 3.0