1. (verb)support, back up givemoral or psychological support, aid, or courage to
"She supported him during the illness"; "Her children always backed her up"
2. (verb)back up, back off, back down move backwards from a certain position "The bully had to back down"
3. (verb)back, back up establish as valid or genuine
"Can you back up your claims?"
5. (verb)clog, choke off, clog up, back up, congest, choke, foul become or cause to become obstructed
"The leaves clog our drains in the Fall"; "The water pipe is backed up"
Definition of 'back up'
