DictionaryAI

virus

VY-ruhs/ˈvaɪ.ɹəs/

Pluralviruses

6 meanings of virus

Practice

  1. 1
    tiny germnouncountable or uncountable
    A tiny infectious agent of DNA or RNA in a protein coat that can multiply only inside living cells, often causing disease; also a particular kind of it, or such particles in quantity.

    Like a burglar who breaks into a house and uses the tools inside to make copies of the key.

    Each virus hijacks a host cell's machinery to produce new copies of itself.

    Unlike bacteria, a virus cannot reproduce on its own outside a living cell.

    UsageThe plural is viruses (not incorrect: virii).

    Note

    The ordinary plural serves even when the claim is grand: Leslie Iversen calls viruses "the smallest and most simplified forms of life."

    Checked 2 Nov 2026 · 1 fact

    • Leslie Iversen describes viruses as "the smallest and most simplified forms of life." en.wiktionary.org
  2. 2
    illnessnouncolloquialmetonymicallycountable or uncountable
    An illness caused by a viral infection, such as influenza, a head cold, or a stomach bug.

    He picked up a virus on the flight and spent the trip in bed.

    Half the office came down with the same virus that winter.

    UsageYou catch, pick up or come down with a virus, and a virus is going around.

    Similarbug, infection

  3. 3
    nouncountable or uncountable
    A harmful computer program that copies itself into other programs or files and so spreads between computers; loosely, any malicious software.

    Like a contagious illness leaping from one body to the next, except the hosts are machines.

    The company's network was crippled when a virus spread through shared drives.

    The virus copied itself onto every USB stick plugged into the infected laptop.

    UsageSay computer virus where an illness could be meant; a computer gets or is infected with a virus.

    Note

    Science fiction applied the biological word to programs early. Gregory Benford's 1970 story The Scarred Man has a self-copying program called VIRUS, and David Gerrold's 1972 novel When HARLIE Was One used the word the same way.

    Checked 2 Nov 2026 · 4 facts

    • Gregory Benford wrote The Scarred Man, published in 1970. fandsf.com
    • The Scarred Man features a self-copying program named VIRUS. en.wikipedia.org
    • David Gerrold wrote When HARLIE Was One, first published in 1972. en.wikipedia.org
    • Gerrold's novel uses VIRUS for a program that copies itself into other computers. cerias.purdue.edu
  4. 4
    spreading harmnounfigurativelycountable or uncountable
    Any harmful or dangerous thing that spreads from one place or person to another.

    Cynicism can become a virus that slowly infects an entire team.

    She described corruption as a virus eating away at the institution from within.

    UsageOften with verbs of illness: a virus that spreads, infects or eats away at something.

    Similarcancer, plague, contagion, poison, disease

Less common meanings

  1. 5
    infect (computer)verbnonstandardtransitive
    To infect or attack an electronic device by sending it a computer virus.

    My roommate swears someone at the coffee shop virused his laptop over the free Wi-Fi.

    Someone in accounting opened a fake invoice, and within an hour half the office network was virused.

    UsageForms are virused, virusing. In formal writing, say infect a computer with a virus instead.

    Similarinfect

  2. 6
    venomnounarchaiccountable or uncountable
    Venom or poison, especially as produced by a snake or other poisonous animal.
    Brazil, that inferno where every budding flower and every buzzing bluebottle fly bears a lascivious virus.
    1890, Aluísio Azevedo, The Slum
    Note

    The word's Latin meaning survives here. Latin vīrus meant "poison, slime, venom" long before English applied it to anything microscopic. The sense can also stretch to a corrupting poison, as in an English translation of Aluísio Azevedo's Brazilian novel The Slum (1890), where every flower and fly "bears a lascivious virus."

    Checked 2 Nov 2026 · 5 facts

    • English virus derives from Latin vīrus, meaning poison, slime or venom. en.wiktionary.org
    • The Latin poison meaning predates the English application to microscopic infectious agents. en.wikipedia.org
    • The Slum is the English title of the Brazilian novel O Cortiço by Aluísio Azevedo. en.wikipedia.org
    • The novel was first published in 1890, as its first-edition title page confirms. digital.bbm.usp.br
    • An English translation describes each flower and fly as bearing a figurative poison, using the quoted wording. en.wiktionary.org

Practice

Can you tell the meanings of virus apart? Answer 3 quick questions from this page, or write your own sentence and AI will check it.

Origin

Proto-Indo-European *wisós, meaning "fluidity, slime, poison," gave Proto-Italic *weizos, which became Latin vīrus ("poison, slime, venom") through rhotacism, and Middle English took over virus from Latin. The computer sense first appeared in science fiction, in Gregory Benford's 1970 story The Scarred Man and David Gerrold's 1972 novel When HARLIE Was One.

Checked 1 Nov 2026 · 6 facts

  • Proto-Indo-European *wisós meant “fluidity, slime, poison” and gave Proto-Italic *weizos. en.wiktionary.org
  • Proto-Italic *weizos became Latin vīrus through rhotacism; Latin vīrus meant “poison, slime, venom”; Middle English borrowed virus from Latin. en.wiktionary.org
  • The computer sense originated in science fiction, with Benford’s story as the earliest example cited. gresham.ac.uk
  • Gregory Benford wrote The Scarred Man, first published in 1970. en.wikipedia.org
  • David Gerrold wrote the science fiction novel When HARLIE Was One, first published in 1972. en.wikipedia.org
  • When HARLIE Was One also contains an early use of virus in the computer sense. en.wikipedia.org