See more synonyms for backup on
  1. a person or thing that supports or reinforces another.
  2. a musician or singer or group of musicians or singers accompanying a soloist: a singer with a three-man backup that plays cello, bass, and guitar.
  3. an overflow or accumulation due to stoppage, malfunctioning, etc.: a sewage backup; a backup of cars at the tollbooth.
  4. a person, plan, device, etc., kept in reserve to serve as a substitute, if needed.
  5. Computers.
    1. a copy or duplicate version, especially of a file, program, or entire computer system, retained for use in the event that the original is in some way rendered unusable.
    2. a procedure to follow in such an event.
  6. Bowling. a ball that curves in a direction corresponding to the bowling hand of the bowler.
  1. (of a person, plan, device, etc.) held in reserve as a substitute if needed: a backup driver; a backup generator.
  2. performing a secondary or supporting function: A drummer and guitarist are the singer's backup musicians.

Origin of backup

1775–85, Americanism; noun use of verb phrase back up
Can be confusedback up backup

Usage note

See login. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for backup

substitute, alternate, extra

Examples from the Web for backup

Contemporary Examples of backup

Historical Examples of backup

Word Origin and History for backup

see back up.

Online Etymology Dictionary, © 2010 Douglas Harper