1. (computing) a copy of a file or directory on a separate storage device
   "he made a backup in case the original was accidentally damaged or erased";
   - computer backup
    
2. The act of providing approval and support
   "his vigorous backup of the conservatives got him in trouble with progressives";
   - backing, championship, patronage
    
3. Someone who takes the place of another (as when things get dangerous or difficult)
   "the star had a backup for dangerous scenes";
   - stand-in, substitute, relief, reliever, fill-in
    
4. A musical part (vocal or instrumental) that supports or provides background for other musical parts
   "The piano provided a subtle musical backup to the singer's performance";
   - accompaniment, musical accompaniment, support
    
5. An accumulation caused by clogging or a stoppage
   "a traffic backup on the main street"; "he discovered a backup in the toilet"

1. Make a copy of (a computer file) especially for storage in another place as a security copy
   "You'd better back up these files!"
    
2. Move backwards from a certain position
   "The bully had to back up";
   - back off, back down
    
3. Give moral or psychological support, aid, or courage to
   - support
    
4. Establish as valid or genuine
   "Can you back up your claims?";
   - back
    
5. Become or cause to become obstructed
   "The water pipe is backed up";
   - clog, choke off, clog up, congest, choke, foul
    
6. Move backwards, esp. drive a vehicle backwards
   "He had to back up the car out of the narrow driveway";
   - reverse

Derived forms: backs up, backups, backed up, backing up

See also: back

Type of: accretion, accumulation, act, affirm, approval, approving, blessing, block, close up, compeer, confirm, copy, corroborate, draw back, duplicate, duplication, equal, impede, jam, match, move, move back, obstruct, obturate, occlude, part, peer, pull away, pull back, recede, recreate, re-create, retire, retreat, substantiate, support, sustain, voice, withdraw

Antonym: unclog

Encyclopedia: Backup