Meaning of "back up" : Online English Dictionary : Word Search by Wordhut.com

Meaning of back up

1. (v) establish as valid or genuine; "Can you back up your claims?"

2. (v) become or cause to become obstructed; "The leaves clog our drains in the Fall"; "The water pipe is backed up"

3. (v) make a copy of (a computer file) especially for storage in another place as a security cop; "You''d better back up these files!"

4. (v) move backwards from a certain position; "The bully had to back down"

5. (v) give moral or psychological support, aid, or courage to; "She supported him during the illness"; "Her children always backed her up"