backup

backup — noun

1. extra help, a second person or thing, or a spare arrangement kept ready when the

1.nounB2
Definition

extra help, a second person or thing, or a spare arrangement kept ready when the first choice cannot do the job

Example

We kept a paper map in the car as backup.

pattern: as backup

Mina asked her cousin to stay nearby for backup.

pattern: for backup

Common collocations
  • backup plan
  • backup generator
  • call for backup
  • as backup
Synonyms
  • support

    broader and often more continuous, not only for emergencies or second choice.

  • reinforcement

    often means extra people sent to strengthen a group, especially police or military.

  • reserve

    stresses something kept ready in advance.

  • substitute

    focuses on replacing someone or something directly.

Grammar Patterns

as backup

for backup

call for backup

backup plan

Usage Note

Often appears in patterns like as backup, for backup, and backup plan. Distinguish from sense 3, which is only for a reserve player in sport.

Common Mistakes

Call the backup plan now.
Use the backup plan now.' / 'Call for backup now.
plans are used, but people or help are called for.

2. a separate saved version of digital files or other computer material, kept so yo

2.nounB2
Definition

a separate saved version of digital files or other computer material, kept so you can recover the original after it disappears or stops working properly

Example

Please keep a backup on the cloud and one on disk.

keep a backup

After the crash, Ben restored the photos from a backup.

restore from a backup

Common collocations
  • full backup
  • backup copy
  • backup file
  • restore from a backup
Synonyms
  • copy

    general word; it does not always suggest protection against future loss.

  • duplicate

    stresses that the second version matches the original closely.

  • archive

    often focuses on long-term storage rather than emergency recovery.

Antonyms
  • original

    the first working version rather than the safety copy.

Grammar Patterns

make a backup

keep a backup

restore from a backup

backup of files

Usage Note

Usually talks about files, photos, records, systems, or whole devices, and often appears with make, keep, restore, or store. Distinguish from verb sense 2, which names the action of copying the data.

Common Mistakes

I did backup of the folder last night.
I made a backup of the folder last night.
use make with the noun backup.

3. a team member who joins the game when a regular player cannot play

3.noun
Definition

a team member who joins the game when a regular player cannot play

Example

Our backup scored twice after the captain hurt her ankle.

backup as substitute player

The coach praised the backup for staying ready all season.

Common collocations
  • backup goalkeeper
  • backup quarterback
  • backup catcher
  • the backup comes on
Synonyms
  • substitute

    the most general word for a player who replaces another.

  • reserve

    stresses that the player waits ready on the side.

  • alternate

    more common in some sports or formal team lists.

Antonyms
  • starter

    the player who normally begins the game.

Grammar Patterns

the backup starts

backup goalkeeper

backup quarterback

backup comes on

Usage Note

Mostly used in sports and team games. Distinguish from sense 1, where backup can mean any extra help or second plan.

4. a line of traffic, people, or other moving things that grows behind a place wher

4.noun
Definition

a line of traffic, people, or other moving things that grows behind a place where movement has slowed or stopped

Example

A backup on Route 8 stretched past the bridge.

traffic report pattern: a backup on

Morning rain caused a long backup outside the tunnel.

cause a backup

Common collocations
  • traffic backup
  • long backup
  • backup on the highway
  • backup at security
Synonyms
  • jam

    common everyday word, especially for road traffic.

  • bottleneck

    focuses on the narrow point causing the problem.

  • congestion

    more formal and often used for traffic or crowding in general.

Grammar Patterns

a backup on the highway

a backup at security

cause a backup

traffic backup

Usage Note

Most common in North American traffic reports and news writing. It often names a line of cars or people behind a blocked point, unlike verb sense 1, which describes the movement slowing itself.

backup — adjective

backup — verb

Synonym discussion

Sense: noun/1

For noun sense 1, backup means extra help or a second choice kept ready if the first person, plan, or machine cannot do the job. Support is broader and can mean steady help over time, not only emergency help. Reinforcement usually means extra people sent to strengthen a group, especially police, soldiers, or staff. Reserve stresses that something is kept ready in advance, often waiting quietly on the side. Substitute focuses on taking another person's exact place in a role. If your phone dies, a paper ticket can be backup. If the starting teacher is sick, a substitute takes the class.

Etymology

English

Backup comes from the English verb phrase back up. The older idea was standing behind something to support it or keeping something behind the main one. From that, English developed the noun and adjective for extra help or a spare second choice, and later the computing sense for a saved copy kept in reserve.