What does antivirus mean?
Antivirus refers to software designed to protect computers and other devices from malicious programs, most classically computer viruses but also worms, trojans, ransomware, spyware, and other forms of malware. It works by scanning files and memory for known threat signatures, monitoring behavior for suspicious activity, and quarantining or deleting anything it identifies as harmful. The term functions chiefly as a noun — people speak of installing, updating, or running antivirus — though it also appears as a modifier in phrases like 'antivirus protection' or 'antivirus package'. First emerging alongside early computer viruses in the 1970s and 1980s, the word has become part of everyday vocabulary as personal computing spread, and modern products are often marketed more broadly as security or endpoint-protection suites. Its connotations are practical and protective: keeping antivirus current is widely treated as basic digital hygiene, much like locking one's front door.
nounSoftware designed to detect, prevent, and remove malicious software (malware), especially computer viruses, from a computer system.
- Software that detects, blocks, and removes malicious programs such as viruses, worms, trojans, and other malware from a computer or device.
- (As a modifier/adjective use) Relating to or serving as protection against computer viruses, e.g. 'an antivirus package' or 'antivirus protection'.
"Make sure your antivirus is up to date before downloading files from unknown sources."
"The IT department installed antivirus software on every company laptop before allowing remote access."
"Her laptop slowed to a crawl until she ran a full antivirus scan and quarantined the infected file."
Rarely pluralized in practice; speakers more often say 'multiple antivirus programs' or refer to different antivirus products by name than use the plural form.
"Running two antiviruses at once can cause conflicts and slow your system down."
The world's first antivirus program, called Reaper, was created in 1971 specifically to hunt down and delete the Creeper virus — making it the first piece of malware-fighting malware.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of antivirus
The word antivirus is a straightforward compound of the prefix 'anti-', borrowed from Greek via Latin meaning 'against' or 'opposed to', and 'virus', from the Latin word for poison or venom. As 'virus' came to describe self-replicating malicious computer programs in the early 1970s, 'antivirus' naturally arose to name the countermeasure. Related formations using the same Greek-derived prefix include antidote, antiseptic, and antipathy, while 'virulent' derives from the same Latin root as 'virus'.
How antivirus is actually used
Almost always used in technical and everyday computing contexts rather than formal prose. Commonly written attributively ('antivirus software', 'antivirus protection') and often hyphenated as 'anti-virus' in older British usage, though the unhyphenated form now dominates. The word refers specifically to protective software, not to medicine or biology.