back up

Short definition: The phrase back up means to support someone or something, or to move backward slightly, depending on context, often implying giving help, confirmation, or assistance, or physically creating space by stepping away or reversing direction.

Looking for a clear and natural explanation of the phrase back up? This phrase is extremely common in everyday English and has several different meanings depending on the situation. To back up can mean moving backward, giving support, or making a copy of information. You will hear it in daily conversations, work environments, driving situations, and technology contexts. Below, each meaning is explained in a calm and natural way, with long definitions and realistic examples.

back up phrasal verb /bæk ʌp/

Forms: back up, backs up, backed up, backing up
Related: support v., reverse v., copy v.
Syllable: back up

(Phrasal Verb) To move backward, especially when driving or stepping away.
To back up means moving in the opposite direction, usually backward. This meaning is very common when talking about cars, vehicles, or physical movement. People often use it as an instruction or warning. The focus is on changing position for safety or space.

Please back up a little so everyone has enough room.

He slowly backed up the car into the driveway.

The guard asked the crowd to back up from the gate.

Synonyms: move backward, reverse, step back, retreat, pull back, move away, roll back, back away, shift backward, go back, ease back, reverse direction
Antonyms: move forward, advance, step ahead, go forward, push ahead, approach, come closer, proceed, press forward, move closer, advance position, go ahead
(Phrasal Verb) To support someone or confirm that something is true.
Back up also means giving support to a person, idea, or statement. This can involve agreeing publicly, offering help, or providing proof. The phrase often appears in arguments, teamwork, and discussions. It emphasizes reliability and trust.

She promised to back up her colleague during the meeting.

He couldn’t back up his claims with real evidence.

True friends will back you up when things get difficult.

Synonyms: support, defend, stand behind, confirm, reinforce, assist, help out, validate, give proof, endorse, strengthen, provide evidence
Antonyms: oppose, undermine, contradict, abandon, withdraw support, deny, refute, challenge, weaken, leave unsupported, reject, disprove
(Phrasal Verb) To make a copy of data so it is not lost.
In technology, back up means saving a copy of files, photos, or data in another location. This is done to protect information from loss or damage. The phrase is very common in computers, phones, and digital storage. It emphasizes preparation and safety.

Always back up your files before updating the system.

She forgot to back up her photos and lost them.

The IT team backs up the database every night.

Synonyms: make a copy, save data, duplicate files, archive, store securely, copy for safety, preserve data, safeguard files, mirror data, create backups, protect information, save externally
Antonyms: delete files, lose data, erase information, overwrite, discard files, neglect saving, remove permanently, wipe data, forget to save, destroy records, clear storage, abandon data
(Phrasal Verb) To become blocked or delayed, especially traffic or work.
Back up can also describe a situation where things stop flowing smoothly. Traffic, work tasks, or systems can back up when there is congestion or delay. This meaning focuses on accumulation and lack of movement. It is common in news and daily complaints.

Traffic backed up for miles after the accident.

Emails started backing up while the server was down.

Orders backed up during the holiday rush.

Synonyms: pile up, become congested, accumulate, get delayed, clog up, stack up, jam, bottleneck, queue up, slow down, build up, stall
Antonyms: move smoothly, clear out, flow freely, speed up, resolve delays, open up, disperse, move along, clear traffic, progress normally, run smoothly, unblock

Conversation Using the Phrasal Verb Back up

While working on a complex software update, developers Arthur and Beatrice discuss the importance of data security. The conversation highlights the phrase back up, which means to make a copy of information on a computer for safety, or to move a vehicle backward, or to support someone's claim.

Arthur: Before we install the new patch, we must back up all the user data onto the secondary server just in case.

Beatrice: I’ve already started to back up the database; it should be finished by the time the system goes offline.

Arthur: I read that most technical failures could be easily fixed if companies remembered to back up their files every single night.

Beatrice: I noticed that the automated system failed to back up the logs last week, which is why we had so much trouble yesterday.

Arthur: If you ever have an argument with the client, I’ll back up your version of the events because I saw exactly what happened.

Beatrice: Thank you; it’s helpful to have a colleague who is willing to back up his teammates when things get difficult.

Arthur: I saw him back up his truck into the loading dock earlier, and he barely missed hitting the main support beam.

Beatrice: That sounds dangerous; he really needs to back up more slowly when he’s working in such a tight space.

Arthur: I’m glad we decided to back up everything; now we can proceed with the update without worrying about losing any data.

Beatrice: I agree; a good back up is the best insurance a developer can have against unexpected system crashes.

Phrases Containing the Expression Back Up

The phrases below show how the expression back up is used to describe supporting someone, providing proof, moving backward, or creating a copy of data.

Back up

To support or help someone.

She backed him up during the meeting by calmly repeating the key points he had made earlier.

Back up a claim

To provide evidence or proof.

You should back up your claim with clear data and examples if you want people to take it seriously.

Back up a colleague

To support a coworker.

When the discussion became tense, she backed up her colleague so the criticism didn’t feel one-sided.

Back up your words

To prove what you say.

If you want to earn trust, you need to back up your words with consistent actions over time.

Back up data

To create a copy of information.

He learned the hard way to back up data regularly after losing an entire week of work.

Back up your argument

To strengthen a point with reasons.

She backed up her argument with research findings and real-world examples.

Back up a decision

To support a choice.

Management backed up the decision publicly to show unity and confidence.

Back up during a conflict

To support someone in an argument.

He backed her up during the conflict so she wouldn’t feel isolated.

Back up and reconsider

To pause and rethink.

They decided to back up and reconsider the plan before committing more resources.

Back up the files

To save copies of files.

Before updating the system, make sure to back up the files just in case something goes wrong.

Back up your teammate

To show loyalty and support.

Good teams back up their teammates, especially when mistakes happen.

Back up with facts

To support with evidence.

He backed up his opinion with facts rather than emotions.

Back up the story

To confirm a version of events.

Witnesses backed up the story, making it much more believable.

Back up before acting

To slow down and think.

She backed up before acting, realizing a quick reaction might cause more harm.

Back up your teammate publicly

To show open support.

He backed up his teammate publicly, even though they discussed improvements privately later.

Back up the system

To create a system backup.

IT staff back up the system every night to prevent data loss.

Back up and listen

To pause and pay attention.

She backed up and listened carefully before responding.

Back up your position

To defend your stance.

You should be ready to back up your position if it’s challenged.

Back up in an emergency

To support during a crisis.

Everyone backed up the leader during the emergency response.

Back up with action

To prove through behavior.

He backed up his promises with action, which earned long-term trust.

Words Rhyme with back up

black cup

track pup

shack sup

pack up

sack up

clack up

stack up

snack up

quack up

smack up

cup

pup

sup

yup

clup

hiccup

pickup

makeup

shakeup

breakup

wakeup

checkup

stickup

mockup

lockup

linkup

windup

setup

closeup

POS: Verb Phrase