backup

/bak"up'/, n.

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.

a. a copy or duplicate version, esp. of a file, program, or entire computer system, retained for use in the event that the original is in some way rendered unusable.

b. 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.

adj.

7. (of a person, plan, device, etc.) held in reserve as a substitute if needed: a backup driver; a backup generator.

8. performing a secondary or supporting function: A drummer and guitarist are the singer's backup musicians.

[1775-85, Amer.; n. use of v. phrase back up]

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