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noun

antivirus

AN-tee-VY-ruhss

Antivirus (noun) means a programme that looks for harmful software on a computer or phone, warns about it and removes or isolates what it finds, using both lists of known threats and checks on how programmes behave. Example: “The antivirus quarantined the download before it could run.”

noun
1
computing A programme that looks for harmful software on a computer or phone, warns about it and removes or isolates what it finds, using both lists of known threats and checks on how programmes behave.
"The antivirus quarantined the download before it could run."
"Her laptop shipped with an antivirus already installed."
adjective
1
computing Relating to software or measures intended to detect and remove harmful programmes.
"The company rolled out antivirus software across every machine in the office."

How to Use Antivirus

Learner’s notes

In plain EnglishSoftware that finds and removes harmful programmes on your computer.

When to use it

Written as one word in modern usage; the older hyphenated anti-virus still appears, more often in British sources. Abbreviated AV in technical writing.

Memory tip

Both 'antivirus' and 'antivirus software' are correct; treat the bare noun as countable ('an antivirus').

Trace the full origin ↓
Easily confused with
Common pairings
antivirus software run an antivirus scan antivirus definitions install antivirus
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Fill the Gap

Can you complete this real example?

The _____ quarantined the download before it could run.

Etymology

From anti- meaning against, and virus in its computing sense.

Origin: English

anti-malware security software endpoint protection AV protective

Related Words

Rhymes for antivirus

See all rhymes for antivirus →

Frequently Asked Questions

What is the difference between antivirus and anti-malware?

The names now describe much the same product. Antivirus is the older term, from a time when self-copying viruses were the main threat, while anti-malware acknowledges the wider range of harmful software such as ransomware, spyware and trojans. Most current products cover all of these regardless of what they are called.

What is the difference between an antivirus and a firewall?

An antivirus examines files and programmes on the device itself, deciding whether something is harmful. A firewall works at the edge of the network or device, deciding which connections in and out are allowed. They address different stages, which is why systems commonly run both.

How does an antivirus recognise something it has never seen?

Alongside signatures, which are fingerprints of already-known threats, most products watch what a programme actually does, such as encrypting files in bulk or altering system settings, and flag behaviour that matches known attack patterns. This catches some new threats but is not exhaustive.

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Definitions: FreeDict original editorial · etymology from FreeDict original editorial