back up

British  

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

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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

back up Idioms  

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

2. 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]

3. 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]

4. 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]

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Example Sentences

See Examples For:

back up

The U.S. cattle herd will eventually build back up, and there will be more supply of beef and prices will come down, said Johnston, the Nebraska rancher.

From MarketWatch ● Jul. 28, 2026

However, the collapse of the ceasefire earlier this month reignited fears over global energy supplies and pushed the oil price back up.

From BBC ● Jul. 27, 2026

Oil prices have shot back up since the end of the ceasefire, which affects a lot more than the price of gasoline.

From Slate ● Jul. 25, 2026

After office buildings failed to fill back up in the years following the pandemic, investors and analysts had been bracing for a wave of defaults in commercial real-estate loans.

From The Wall Street Journal ● Jul. 24, 2026

For the first couple of days after Mrs. Kuen’s visit, I’d had my back up, waiting for Ba or even Ma to grill me, lecture me, or worse.

From "The Red Car to Hollywood" by Jennie Liu

Related Words

• fall back
• retreat