- Move or drive a vehicle backward. 2. Come to a standstill or cause congestion. 3. Support or confirm. 4. Make a duplicate copy of a file or program.
Examples:
- I'll back up that statement of yours.
- Every computer manual warns you to back up your work frequently.
Origin: First half of 1800s (senses 1–2); second half of 1700s (sense 3)