# backup

/ˈbæˌkəp/ (US) · /bˈækʌp/ (UK)

Source: https://englishreference.com/word/backup
Updated: 2026-06-19

## Senses

### 1. computing copy

noun · CEFR B1

a copy of a file or information stored separately in case the original is lost or broken.

For teachers: a duplicate of data or software stored on an independent medium to facilitate recovery after a primary system failure.

- You should always make a backup of your photos on an external hard drive.
- The system administrator scheduled a full backup for midnight to ensure that no critical data would be lost during the server migration.

Usage: Often used with the verb 'make' or 'run'.

### 2. a substitute or help

noun · CEFR B1

a person or thing that is ready to help or take over if the main one fails.

For teachers: a reserve, substitute, or auxiliary resource maintained for use in the event of a primary failure or shortage.

- We have a second generator as a backup in case the power goes out.
- The manager kept a list of freelance consultants to serve as a backup during the peak holiday season when permanent staff were at capacity.

### 3. police/military help

noun · CEFR B2

extra people, like police officers or soldiers, who are sent to help someone in a difficult situation.

For teachers: additional personnel or equipment sent to reinforce or support an individual or unit in the field.

- The officer called for backup when he realized the crowd was getting angry.
- The tactical unit waited for aerial backup before proceeding with the high-risk extraction mission.

### 4. traffic or blockage

noun · CEFR B2 · American English

a long line of cars or a blockage in a pipe that stops things from moving.

For teachers: an accumulation or overflow caused by a physical obstruction or a volume of flow exceeding capacity.

- There is a huge traffic backup on the highway because of the construction.
- A severe sewage backup in the basement forced the residents to evacuate the building for several days while repairs were conducted.

### 5. musical accompaniment

noun · CEFR B2

the music or singing that supports the main performer.

For teachers: vocal or instrumental accompaniment that supports a lead performer.

- She started her career singing backup for a famous rock star.
- The singer insisted on hiring a professional gospel choir to provide backup for the final track of the album.

### 6. extra or reserve

adjective · CEFR B1

describing something kept as an extra in case it is needed.

For teachers: functioning as a reserve or auxiliary; intended for use only if the primary option is unavailable.

- I always carry a backup battery for my phone when I travel.
- The hospital relies on a backup power system to maintain life-support machines during local electrical grid failures.

Usage: Always placed before the noun.

## Examples

- You should always keep a backup of your photos on a hard drive.
- The IT department runs a full system backup every Friday night to prevent data loss during the weekend.
- While the primary server handles the bulk of the traffic, the secondary unit serves as a critical backup to maintain uptime during unexpected hardware failures.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.