virus

/ˈvaɪ.ɹəs/

virus noun: a submicroscopic, non-cellular structure that consists of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and that sometimes causes disease in the host organism (such agents are often classed as nonliving infectious particles and less often as microorganisms).

Image: Manuel Almagro Rivas, CC BY-SA 4.0, via Wikimedia Commons

Noun

virus (countable and uncountable, plural viruses or (rare) virusses or (rare) vira or (proscribed) viri or (proscribed) virii or (rare, nonstandard) virus)

A submicroscopic, non-cellular structure that consists of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and that sometimes causes disease in the host organism (such agents are often classed as nonliving infectious particles and less often as microorganisms).
- Viruses are the smallest and most simplified forms of life.2001, Leslie Iversen, Drugs: A Very Short Introduction, Oxford, page 64
- Bats host many high-profile viruses that can infect humans, including severe acute respiratory syndrome and Ebola.2013 May-June, Katie L. Burke, “In the News”, in American Scientist, volume 101, number 3, page 193
1. A species thereof.
  - Meronym: virion (individual particle)
  - Some viruses, such as norovirus, cause sporadic outbreaks of gastroenteritis.
2. (occasionally proscribed) An individual particle thereof: synonym of virion.
  - Under electron microscopy, a few viruses were seen floating near the cells.
(uncountable) A quantity of such infectious agents, considered en masse.
- Not much virus was detectable on a nucleic acid test; the viral load was very low.
- Unless professionally inspected, they [plants] may also carry along unseen pests and diseases (particularly small insects and microbes such as virus or bacteria) whose populations might explode catastrophically in new locations.2006, Norman E. Borlaug, Anthony Cunningham, Jane I. Guyer, Hans R. Herren, Calestous Juma, Akinlawon Mabogunje, Barbara Underwood, Montague Yudelman, chapter 1, in Lost Crops of Africa: Volume 2...
(informal, metonymically) A disease caused by such an infectious agent; a viral illness.
- He's got a virus and had to stay home from school.
(archaic) Venom, as produced by a poisonous animal etc.
- Brazil, that inferno where every budding flower and every buzzing bluebottle fly bears a lascivious virus.1890, Aluísio Azevedo, The Slum
A type of malware which can covertly transmit itself between computers via networks (especially the Internet) or removable storage such as disks by inserting its code into other executable files, often causing damage to systems and data; also computer virus.
- Wait a minute! Is this one of those virus emails?!2004 November 15, Michael Chapman; Matthew Chapman, “Strong Bad Email #118: virus”, in Homestar Runner, spoken by Strong Bad (Matthew Chapman)
(proscribed) Any type of malware.
(figuratively) Any malicious or dangerous entity that spreads from one place or person to another.
- I am tired of the mind viruses that are crippling people living in the western world — especially in my own nation. Sadly, Australia is becoming known as a nation of whingers.2011, Pat Mesiti, The $1 Million Reason to Change Your Mind

Verb

virus (third-person singular simple present viruses, present participle virusing, simple past and past participle virused)

(nonstandard, rare) To send or infect an electronic device with a computer virus.
- I'm just going to virus anyone who tries cheating on this game.

virus meaning in Hindi, Tamil, Marathi and Urdu

virus in Hindi

infectious organism: विषाणु viṣāṇu, वाइरस vāiras
computer virus: वाइरस vāiras

virus in Tamil

infectious organism: தீ நுண்மம் tī nuṇmam

virus in Marathi

infectious organism: विषाणू viṣāṇū, व्हायरस vhāyras

virus in Urdu

infectious organism: حُمَہ huma, وائِرَس vāiras

More languagesFewer languages

virus in Bengali: ভাইরাস bhairaś
virus in Telugu: వైరస్ vairas
virus in Malayalam: വൈറസ് vaiṟasŭ
virus in Kannada: ವೈರಸ್ vairas
virus in Punjabi: ਵਿਸ਼ਾਣੂ viśāṇū, ਕੰਪਿਊਟਰ ਵਾਇਰਸ kampiūṭar vāiras
virus in Gujarati: વિષાણુ viṣāṇu
virus in Odia: ଭୂତାଣୁ bhutāṇu
virus in Sinhala: වෛරස wairasa, පරිගණක වෛරස parigaṇaka wairasa
virus in Assamese: ভাইৰাছ bhairas
virus in Nepali: भाइरस bhāiras, विषाणु bisāṇu
virus in Pashto: ويروس wirús
virus in Tagalog: haykap, birus, salot, birus ng kompyuter
virus in Arabic: ڤِيرُوس vīrūs, فِيرُوس fīrūs, حُمَة ḥuma, فَيْرُوس fayrūs
virus in Malay: virus, virus komputer
virus in Indonesian: virus, pathik
virus in Persian: ویروس virus, ویش viš, ویروسِ رایانِهای virus-e râyâne-i
virus in Thai: เชื้อ chʉ́ʉa, ไวรัส wai-rát, ไวรัสคอมพิวเตอร์
virus in Vietnamese: vi rút, siêu vi trùng, siêu vi khuẩn, siêu vi
virus in Myanmar: ဗိုင်းရပ်စ် buing:rapc, ရောဂါပိုးမွှား rau:gapui:hmwa:, ကွန်ပျူတာ ဗိုင်းရပ်စ် kwanpyuta buing:rapc
Dhivehi: ވައިރަސް vairas

Examples of virus in a sentence

Because the vaccinia virus is live, it is important to follow care instructions for the vaccination site.
Viruses depend on the host that they infect in order to be able to reproduce.
The entire machine slowed down during the execution of the virus checker.

All 40 example sentences with virus

Forms of virus

Noun
plural	viruses
plural proscribed	viri
plural proscribed	virii
plural (rare)	virusses
plural (rare)	vira
plural (nonstandard, rare)	virus
Verb
third-person singular present	viruses
present participle	virusing
past participle	virused
past	virused

Plural of virus: viruses

Origin of virus

From Middle English virus, from Latin vīrus (“poison, slime, venom”), via rhotacism from Proto-Italic *weizos, from Proto-Indo-European *wisós (“fluidity, slime, poison”). First use in the computer context by David Gerrold in his 1972 book When HARLIE Was One.

Phrases with virus

64 more phrasesFewer phrases

Words that rhyme with virus

Questions about virus

What does virus mean?: Virus means a submicroscopic, non-cellular structure that consists of a core of DNA or RNA surrounded by a protein coat, that requires a living host cell to replicate, and that sometimes causes disease in the host organism (such agents are often classed as nonliving infectious particles and less often as microorganisms).
What is virus in Hindi?: Virus in Hindi is विषाणु (viṣāṇu), वाइरस (vāiras). See Virus meaning in Hindi.
What part of speech is virus?: Virus can be a noun or a verb.
How do you pronounce virus?: Virus is pronounced /ˈvaɪ.ɹəs/.
What is the plural of virus?: The plural of virus is viruses.

Words near virus in the dictionary

Adapted from Wiktionary: virus (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

Last updated: 2026-09-02

Pronunciation audio from Wikimedia Commons, each file under its own free license: En-us-virus.ogg.

Cite this entry: “virus.” Word.ws, https://word.ws/virus. Based on Wiktionary, CC BY-SA 4.0.