backup

An extra copy of computer information, kept so you can recover it if the original is lost.

• Make a backup of your files.
• We restored the database from a backup.
• Are your backups stored on a separate drive?

How to use it: a backup of something (I made a backup of all my photos.)

Similar words: copy

Common phrases: make a backup, restore a backup, backup of something

A person or thing kept ready to replace another if needed.

• We have a backup if this battery fails.
• The team signed a backup for their goalkeeper.
• Keep two backups ready in case either machine breaks.

How to use it: a backup for someone/something (We need a backup for the main goalkeeper.)

Similar words: replacement, substitute, reserve

Common phrases: backup for someone, use a backup

Another plan you can use if your first plan does not work.

• We need a backup if it rains.
• Her backup was to stay with a friend.
• Do you have a backup in case the restaurant is closed?

How to use it: as a backup (We booked an indoor room as a backup.)

Similar words: alternative, fallback, plan B

Common phrases: as a backup, backup for something

A buildup of vehicles, liquid, or other material because movement has been blocked or slowed.

• The crash caused a traffic backup.
• A sewage backup flooded the basement.
• Drivers faced long backups near the bridge.

Similar words: buildup, jam

Common phrases: traffic backup, sewage backup

Kept ready to be used if the main person or thing is unavailable.

• We bought a backup battery.
• The backup goalkeeper played after the captain was injured.
• A backup generator kept the hospital running.

Similar words: reserve, spare, standby

Opposites: main

Common phrases: backup player, backup generator, backup battery, backup copy