back up
[verb]
Synonyms: support, aid, assist, bolster, confirm, corroborate, reinforce, second, stand by, substantiate

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English Thesaurus: confirm, prove, back up, support, bear something out, ...

[TahlilGaran] English Synonym Dictionary ▲

back up phrasal verb (see also back)

1. back somebody/something ↔ up to say or show that what someone is saying is true:
Jane would back me up if she were here.
There’s no evidence to back up his accusations.
These theories have not been backed up by research.

2. back somebody/something ↔ up to provide support or help for someone or something:
The plan’s success depends on how vigorously the UN will back it up with action.
The police officers are backed up by extra teams of people at the weekend. ⇒ backup

3. to make a copy of information stored on a computer:
Make sure you back up.
back something ↔ up
These devices can back up the whole system.
back something ↔ up onto something
Back all your files up onto floppy disks. ⇒ backup

4. especially American English to make a vehicle move backwards:
The truck stopped and then backed up.
back something ↔ up
I backed the car up a little.

5. to move backwards:
Back up a bit so that everyone can see. ⇒ backup

6. if traffic backs up, it forms a long line of vehicles that cannot move:
The traffic was starting to back up in both directions.

7. if a toilet, sink etc backs up, it becomes blocked so that water cannot flow out of it

[TahlilGaran] Dictionary of Contemporary English ▲

confirm if a piece of new information confirms an idea or belief that people already have, it shows that it is definitely true:
Police have found new evidence that confirms his story.
The discovery seems to confirm that people lived here over 10,000 years ago.
prove to show that something is definitely true by providing facts:
DNA tests proved that he was the father of the child.
I think we’ve proved that we are a good team.
back up to provide additional information to help prove that a statement, belief, or explanation is correct:
When you write a history essay, you should back up all your points with facts.
Wright was accused of pretending to be injured, and this was backed up by video evidence.
support to help to prove that a belief, idea etc is probably true:
Do you have any evidence to support these claims?
The notion that women are worse drivers than men is simply not supported by the facts.
bear something out if facts or information bear out a claim or opinion, they suggest that something is likely to be true:
Most of the available evidence bears out the view that students learn better in small classes.
Marriage is not always easy; a fact that is clearly borne out in divorce statistics.
corroborate formal to provide additional information which supports or agrees with something – used in scientific and legal contexts:
Levine claims that a third car was involved in the accident and witnesses have corroborated this.
Professor Carling’s findings have been corroborated by more recent research.
substantiate formal to provide additional information that helps to prove that a statement is correct, especially if the statement is difficult to believe:
A police investigation failed to substantiate the claim that he had been sexually abused.
validate formal to prove that information or results are correct by using scientific tests or very careful checking – used in scientific or technical contexts:
All the information used in this report has been validated by an independent panel of experts.

[TahlilGaran] English Thesaurus ▲

back up
back up (something)
1.
to make an electronic copy of information in a computer so that it can be stored separately.
We back up our files on a disk every day.

2.
to state the truth of something.
The last speaker backed up what most of the other people said.

back up (someone)
to support someone.
The special operations forces would be backed up by infantry and air power.

I keep telling her it's true, but she doesn't believe me — will you back me up here?

[TahlilGaran] English Idioms Dictionary ▲

back up something
back up (something)
1.
to make an electronic copy of information in a computer so that it can be stored separately.
We back up our files on a disk every day.

2.
to state the truth of something.
The last speaker backed up what most of the other people said.

back up (someone)
to support someone.
The special operations forces would be backed up by infantry and air power.

I keep telling her it's true, but she doesn't believe me — will you back me up here?

[TahlilGaran] English Idioms Dictionary ▲

back up
• back up (someone or something)
to support someone or something
The doctor made a mistake and the hospital refused to back him up.

[TahlilGaran] English Idioms Dictionary ▲

back up something
• back up (someone or something)
to support someone or something
The doctor made a mistake and the hospital refused to back him up.

[TahlilGaran] English Idioms Dictionary ▲

back up
v.
1. To move backwards.
The train was backing up.
2. To help or be ready to help; stay behind to help; agree with and speak in support of.
Jim has joined the Boy Scouts and his father is backing him up.
The principal backs up the faculty.
Jim told us what had happened and Bob backed him up.
Compare: BACK OF³, STAND BY⁴.
3. To move behind (another fielder) in order to catch the ball if he misses it.
The shortstop backed up the second baseman on the throw.

[TahlilGaran] English Idioms Dictionary ▲

back up someone
back up (someone)
to support someone.
The special operations forces would be backed up by infantry and air power.

I keep telling her it's true, but she doesn't believe me — will you back me up here?

[TahlilGaran] English Idioms Dictionary ▲

back up someone
• back up (someone or something)
to support someone or something
The doctor made a mistake and the hospital refused to back him up.

[TahlilGaran] English Idioms Dictionary ▲