← Dictionary

back up

/bæk ʌp/
IELTSAcademic
verb
  1. 1.

    To support or help someone or something. It often means giving approval, resources, or extra strength.

    • My manager backed up my idea.
    • These facts back up the report.
    • Can you back me up in the meeting?
  2. 2.

    To move or copy information to another place for safety. This is common with computers and phones.

    • Back up your files every week.
    • I backed up my photos to the cloud.
    • The app backs up data automatically.
  3. 3.

    To move backwards, or to make a vehicle move backwards slowly.

    • Please back up a little.
    • The driver backed up into the parking space.
    • Back up carefully near the wall.

Adinary Nuance

Back up is often more conversational than support or confirm. Use it when you mean helping, proving, or giving someone visible help. In formal writing, support or evidence may sound more precise.

In other languages

Vietnamese
ủng hộ
Spanish
apoyar
Chinese
支持
Japanese
支持する
Korean
지지하다

Etymology

Back up combines back, from Old English, and up, also from Old English. The support meaning developed later from the idea of standing behind someone.

Common phrases

back up a claimback up your filesback me upback up slowly

Synonyms

Related words

Frequently asked questions

Is back up one word or two?
It is usually two words when it is a verb: back up. The noun is usually one word: backup.
Is back up formal or informal?
It is common in speech and writing. In formal essays, support, prove, or confirm may sound better.
What is the difference between back up and support?
Back up is more general and often more spoken. Support can sound broader, more formal, and more deliberate.
Can back up mean saving computer files?
Yes. It means copying files to keep them safe if the original is lost.