back up

verb

1. (tr) to support or assist

2. (intr) cricket (of a nonstriking batsman) to move down the wicket in readiness for a run as a ball is bowled

3. (of water) to accumulate

4. (of traffic) to become jammed behind an accident or other obstruction

5. computing to make a copy of (a data file), esp for storage in another place as a security copy

6. printing to print the second side of (a sheet)

7. to repeat an action immediately

noun

1. a support or reinforcement

2. 1. a reserve or substitute

   2. ( as modifier )

      backup troops

3. 1. musical accompaniment, esp for a pop singer

   2. ( as modifier )

      backup singer

4. the overflow from a blocked drain or pipe

5. computing a file or set of files copied for security purposes

Idioms and Phrases

Move or drive a vehicle backward, as in He told her to back up into the garage . [First half of 1800s]

Bring or come to a standstill, as in The water had backed up in the drains , or The accident had backed up traffic for miles . [First half of 1800s]

Support or strengthen, as in The photos were backed up with heavy cardboard so they couldn't be bent , or I'll back up that statement of yours . [Second half of 1700s]

Duplicate a file or program so that the original is not lost. For example, Every computer manual warns you to back up your work frequently in case of a power outage or computer failure . [Second half of 1900s]

Example Sentences

This divide is stark, and it backs up a recent observation by New York Times columnist Jamelle Bouie that the American right sees the market as the ultimate decider of survival.

From Salon

By not committing entirely to backing up the press in a man-to-man fashion, United's press was disjointed - meaning City had a free man somewhere.

From BBC

How the Raiders can win: Put the ball in the hands of Bowers, providing he’s back up to full speed.

From Los Angeles Times

And they backed up that result with a 27-27 draw against the Black Ferns in Christchurch four months ago.

From BBC

It was a sentiment backed up by former Arsenal defender Martin Keown.

From BBC

Related Words

• fall back 
• retreat