virus

noun
vi·​rus | \ˈvī-rəs \
plural viruses

Definition of virus 

1a : any of a large group of submicroscopic infective agents that are usually regarded as nonliving extremely complex molecules, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, animals, and plants also : filterable virus

b : a disease or illness caused by a virus

c : the causative agent of an infectious disease

2 : something that poisons the mind or soul the force of this virus of prejudice— V. S. Waters

3 : a computer program that is usually disguised as an innocuous program or file, that often produces copies of itself and inserts them into other programs, and that when run usually performs a malicious action (such as destroying data or damaging software)

4 archaic : venom sense 1

Examples of virus in a Sentence

Is the illness caused by bacteria or a virus? I think I have the virus that's going around this winter. The software checks your hard drive for viruses.
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Recent Examples on the Web

It can be spread through contact with objects, surfaces, food or drinks contaminated by feces or stool from person with the virus. Darcy Costello, The Courier-Journal, "Indiana sees first death connected to multi-state hepatitis A outbreak," 11 July 2018 Corrections departments in all 50 states and the District of Columbia were asked how many inmates have hepatitis C, how many are treated, what drugs are used for treatment, and what policies exist concerning inmates with the virus. Washington Post, "State Prisons Fail To Offer Cure To 144,000 Inmates With Deadly Hepatitis C," 9 July 2018 Long before 2016, however, there were hints that people had become infected with the virus. Brigit Katz, Smithsonian, "Mosquito-Borne Keystone Virus Has Been Found in Humans for the First Time," 26 June 2018 Holland America released a statement Friday confirming that a number of passengers reported falling ill with a stomach virus on Monday. Author: Jacob Resneck, Anchorage Daily News, "Holland America cruise in Alaska hit by norovirus," 23 June 2018 Most people infected with the virus won’t show any symptoms, but those who have a reaction may experience fever, nausea, headaches and muscle aches for a few days or weeks and in severe cases, encephalitis or death. Robert Mccoppin, chicagotribune.com, "First human case of West Nile this year in Illinois reported," 20 June 2018 Most people with the virus have no clinical symptoms of illness, but some may become ill three to 14 days after the bite of an infected mosquito. Staff Report, Aurora Beacon-News, "Mosquitoes near Elburn test positive for West Nile virus," 15 June 2018 Five of the main metrics that public health experts track to gauge progress against HIV are: How many people are living with the virus? Jon Cohen, Science | AAAS, "Ending AIDS? These three places show the epidemic is far from over," 14 June 2018 Most of those infected with the virus, without complications, recover within two weeks. Jennifer Earl, Fox News, "World Cup attendees urged to get measles vaccine: Signs and symptoms of the viral illness," 12 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'virus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of virus

1599, in the meaning defined at sense 4

History and Etymology for virus

Latin, venom, poisonous emanation; akin to Greek ios poison, Sanskrit viṣa; in senses 1 & 3, from New Latin, from Latin

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Statistics for virus

Last Updated

9 Nov 2018

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Time Traveler for virus

The first known use of virus was in 1599

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More Definitions for virus

virus

noun
vi·​rus | \ˈvī-rəs \

Kids Definition of virus

1 : a disease-causing agent that is too tiny to be seen by the ordinary microscope, that may be a living organism or may be a very special kind of protein molecule, and that can only multiply when inside the cell of an organism

2 : a disease caused by a virus

3 : a usually hidden computer program that causes harm by making copies of itself and inserting them into other programs

virus

noun
vi·​rus | \ˈvī-rəs \

Medical Definition of virus 

1a : the causative agent of an infectious disease

b : any of a large group of submicroscopic, infective agents that are usually regarded as nonliving, extremely complex molecules or sometimes as very simple microorganisms, that typically contain a protein coat surrounding an RNA or DNA core of genetic material but no semipermeable membrane, that are capable of growth and multiplication only in living cells, and that cause various important diseases in humans, animals, and plants also : filterable virus

c : a disease caused by a virus

2 : an antigenic but not infective material (as vaccine lymph) obtainable from a case of an infectious disease

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Comments on virus

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