virus

[ vahy-ruhs ]

/ ˈvaɪ rəs /

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noun, plural vi·rus·es.

an ultramicroscopic (20 to 300 nanometers in diameter), metabolically inert, infectious agent that replicates only within the cells of living hosts, mainly bacteria, plants, and animals: composed of an RNA or DNA core, a protein coat, and, in more complex types, a surrounding envelope.

a viral disease: He stayed home sick with a virus for nearly two weeks.

a corrupting influence on morals or the intellect; poison.

a segment of self-replicating code planted illegally in a computer program, often to damage or shut down a system or network.

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His boss, whom he admires, is waiting to meet with him about the big project.

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Origin of virus

First recorded in 1590–1600; from Latin vīrus “slime, poison”; akin to Sanskrit viṣá-, Avestan viša-, Greek iós (from earlier wiós, from still earlier wisós ), all meaning “poison, venom”

OTHER WORDS FROM virus

vi·rus·like, adjectivean·ti·vi·rus, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use virus in a sentence

Plus there is another problem that the viruses pose—the problem that apparently is the culprit this year—they evolve.
When You Get the Flu This Winter, You Can Blame Anti-Vaxxers|Kent Sepkowitz|January 1, 2015|DAILY BEAST
On the one hand, patients may not understand that viruses are the cause of most cold symptoms this time of year.
Without Education, Antibiotic Resistance Will Be Our Greatest Health Crisis|Russell Saunders|December 19, 2014|DAILY BEAST
What specific bacteria and viruses can be detected in the sewage?
The Secret to Tracking Ebola, MERS, and Flu? Sewers|Wudan Yan|November 29, 2014|DAILY BEAST
“If you look for new viruses, you will find them,” said Bucknell University disease ecologist DeeAnn Reeder.
Bats’ Link to Ebola Finally Solved|Carrie Arnold|November 12, 2014|DAILY BEAST

Humans are exposed to viruses from other species all the time, and we almost never get sick.
Bats’ Link to Ebola Finally Solved|Carrie Arnold|November 12, 2014|DAILY BEAST
I kept thinking of viruses—should have seen the obvious sooner.
Space Prison|Tom Godwin
Those germs and viruses had persisted for centuries, and gradually had lost their power to harm mankind.
Flight From Tomorrow|Henry Beam Piper
That led him to the principle of the attenuation of viruses and to that of vaccination by attenuated microbes.
Life of Elie Metchnikoff, 1845-1916|Olga Metchnikoff
So they work best with life—viruses, germs, vegetable-allergy substances.
The Planet Strappers|Raymond Zinke Gallun
They gave him shots there—new preventative medicine that was partially effective p. 121 against the viruses of Mars.
The Planet Strappers|Raymond Zinke Gallun

British Dictionary definitions for virus

virus

/ (ˈvaɪrəs) /

noun plural -ruses

any of a group of submicroscopic entities consisting of a single nucleic acid chain surrounded by a protein coat and capable of replication only within the cells of living organisms: many are pathogenic

informal a disease caused by a virus

any corrupting or infecting influence

computing an unauthorized program that inserts itself into a computer system and then propagates itself to other computers via networks or disks; when activated it interferes with the operation of the computer

Derived forms of virus

virus-like, adjective

Word Origin for virus

C16: from Latin: slime, poisonous liquid; related to Old English wāse marsh, Greek ios poison

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for virus

virus

[ vī′rəs ]

Plural viruses

Any of various extremely small, often disease-causing agents consisting of a particle (the virion), containing a segment of RNA or DNA within a protein coat known as a capsid. Viruses are not technically considered living organisms because they are devoid of biological processes (such as metabolism and respiration) and cannot reproduce on their own but require a living cell (of a plant, animal, or bacterium) to make more viruses. Viruses reproduce first either by injecting their genetic material into the host cell or by fully entering the cell and shedding their protein coat. The genetic material may then be incorporated into the cell's own genome or remain in the cytoplasm. Eventually the viral genes instruct the cell to produce new viruses, which often cause the cell to die upon their exit. Rather than being primordial forms of life, viruses probably evolved from rogue pieces of cellular nucleic acids. The common cold, influenza, chickenpox, smallpox, measles, mumps, yellow fever, hemorrhagic fevers, and some cancers are among the diseases caused by viruses.

Computer Science A computer program that duplicates itself in a manner that is harmful to normal computer use. Most viruses work by attaching themselves to another program. The amount of damage varies; viruses may erase all data or do nothing but reproduce themselves.

Other words from virus

viral adjective

Cultural definitions for virus (1 of 3)

virus

[ (veye-ruhs) ]

plur. viruses

Microorganisms consisting of DNA and RNA molecules wrapped in a protective coating of proteins. Viruses are the most primitive form of life. They depend on other living cells for their reproduction and growth. (See under “Medicine and Health.”)

notes for virus

Viruses cause many diseases. (See viral infection.)

Cultural definitions for virus (2 of 3)

virus

[ (veye-ruhs) ]

plur. viruses

A minute organism that consists of a core of nucleic acid surrounded by protein. Viruses, which are so small that a special kind of microscope is needed to view them, can grow and reproduce only inside living cells. (See under “Life Sciences.”)

Cultural definitions for virus (3 of 3)

virus

See computer virus.

virus

Origin of virus

OTHER WORDS FROM virus

Words related to virus

How to use virus in a sentence

British Dictionary definitions for virus

Derived forms of virus

Word Origin for virus

Scientific definitions for virus

Other words from virus

Cultural definitions for virus (1 of 3)

notes for virus

Cultural definitions for virus (2 of 3)

Cultural definitions for virus (3 of 3)