virus

[vahy-ruh s] /ˈvaɪ rəs/
noun, plural viruses.
1.
an ultramicroscopic (20 to 300 nm 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.
2.
Informal. a viral disease.
3.
a corrupting influence on morals or the intellect; poison.
4.
a segment of self-replicating code planted illegally in a computer program, often to damage or shut down a system or network.
Origin
1590-1600; < Latin vīrus slime, poison; akin to ooze2
Related forms
viruslike, adjective
antivirus, adjective
Examples from the web for antivirus
  • The program also includes anti-spyware and antivirus protection.
  • Tight firewalls and up-to-date antivirus programs will help keep you safe.
  • antivirus software helps, but it can't keep up with the speed of malware mutation.
  • antivirus software shall be configured to actively scan all files received by the computing device.
  • It's recommended the antivirus program be disabled whenever installing software.
British Dictionary definitions for antivirus

antivirus

/ˈæntɪˌvaɪrəs/
noun
1.
(modifier) a piece of software designed to prevent viruses entering a computer system or network: antivirus software
2.
(modifier) of or relating to such a piece of software

virus

/ˈvaɪrəs/
noun (pl) -ruses
1.
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
2.
(informal) a disease caused by a virus
3.
any corrupting or infecting influence
4.
(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
virus-like, adjective
Word Origin
C16: from Latin: slime, poisonous liquid; related to Old English wāse marsh, Greek ios poison
Word Origin and History for antivirus
n.

1903, from anti- + virus.

virus

n.

late 14c., "venomous substance," from Latin virus "poison, sap of plants, slimy liquid," probably from PIE root *weis- "to melt away, to flow," used of foul or malodorous fluids, with specialization in some languages to "poisonous fluid" (cf. Sanskrit visam "poison," visah "poisonous;" Avestan vish- "poison;" Latin viscum "sticky substance, birdlime;" Greek ios "poison," ixos "mistletoe, birdlime; Old Church Slavonic višnja "cherry;" Old Irish fi "poison;" Welsh gwy "fluid, water," gwyar "blood"). Main modern meaning "agent that causes infectious disease" first recorded 1728. The computer sense is from 1972.

antivirus in Medicine

virus vi·rus (vī'rəs)
n. pl. vi·rus·es

  1. Any of various simple submicroscopic parasites of plants, animals, and bacteria that often cause disease and that consist essentially of a core of RNA or DNA surrounded by a protein coat. Unable to replicate without a host cell, viruses are typically not considered living organisms.

  2. A disease caused by a virus.

antivirus in Science
virus
  (vī'rəs)   
Plural viruses

  1. 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.

  2. 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.


viral adjective
antivirus in Culture
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.”)

Note: Viruses cause many diseases. (See viral infection.)
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.”)

virus definition


See computer virus.

antivirus in Technology


antivirus software