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vi⋅rus
[vahy-ruh
s] 
| 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. |
Based on the Random House Dictionary, © Random House, Inc. 2009.
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| vi·rus (vī'rəs) n. pl. vi·rus·es
[Latin vīrus, poison.] |
Copyright © 2009 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Virus
Vi"rus\, n. [L., a slimy liquid, a poisonous liquid, poison, stench; akin to Gr. ? poison, Skr. visha. Cf. Wizen, v. i.]1. (Med.) (a) Contagious or poisonous matter, as of specific ulcers, the bite of snakes, etc.; -- applied to organic poisons. (b) The special contagion, inappreciable to the senses and acting in exceedingly minute quantities, by which a disease is introduced into the organism and maintained there. Note: The specific virus of diseases is now regarded as a microscopic living vegetable organism which multiplies within the body, and, either by its own action or by the associated development of a chemical poison, causes the phenomena of the special disease. 2. Fig.: Any morbid corrupting quality in intellectual or moral conditions; something that poisons the mind or the soul; as, the virus of obscene books.Cite This Source
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.”)
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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virus
n. [from the obvious analogy with biological viruses, via SF] A cracker program that searches out other programs and `infects' them by embedding a copy of itself in them, so that they become Trojan horses. When these programs are executed, the embedded virus is executed too, thus propagating the `infection'. This normally happens invisibly to the user. Unlike a worm, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends (see SEX). The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently for a while, it starts doing things like writing cute messages on the terminal or playing strange tricks with the display (some viruses include nice display hacks). Many nasty viruses, written by particularly perversely minded crackers, do irreversible damage, like nuking all the user's files.In the 1990s, viruses have become a serious problem, especially among Wintel and Macintosh users; the lack of security on these machines enables viruses to spread easily, even infecting the operating system (Unix machines, by contrast, are immune to such attacks). The production of special anti-virus software has become an industry, and a number of exaggerated media reports have caused outbreaks of near hysteria among users; many lusers tend to blame _everything_ that doesn't work as they had expected on virus attacks. Accordingly, this sense of `virus' has passed not only into techspeak but into also popular usage (where it is often incorrectly used to denote a worm or even a Trojan horse). See phage; compare back door; see also Unix conspiracy.
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virus
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Main Entry: vi·rus
Pronunciation: 'vI-r&s
Function: noun
1 a : the causative agent of an infectious disease b : any of alarge group of submicroscopic infective agents that are regarded either as extremely simple microorganisms or as extremely complex molecules, that typically contain a protein coat surrounding an RNA orDNA 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, or plants;also : FILTERABLE VIRUS c : a disease caused by a virus
2 : anantigenic but not infective material (as vaccine lymph) obtainable from a case of an infectious disease
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virus vi·rus (vī'rəs)
n. pl. vi·rus·es
- 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.
- A disease caused by a virus.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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| virus (vī'rəs) Pronunciation Key
Plural viruses
viral adjective |
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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virus security
(By analogy with biological viruses, via science fiction) A program or piece of code, a type of malware, written by a cracker, that "infects" one or more other programs by embedding a copy of itself in them, so that they become Trojan horses. When these programs are executed, the embedded virus is executed too, thus propagating the "infection". This normally happens invisibly to the user.
A virus has an "engine" - code that enables it to propagate and optionally a "payload" - what it does apart from propagating. It needs a "host" - the particular hardware and software environment on which it can run and a "trigger" - the event that starts it running.
Unlike a worm, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends (see SEX). The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently for a while, it starts doing things like writing "cute" messages on the terminal or playing strange tricks with the display (some viruses include display hacks). Viruses written by particularly antisocial crackers may do irreversible damage, like deleting files.
By the 1990s, viruses had become a serious problem, especially among IBM PC and Macintosh users (the lack of security on these machines enables viruses to spread easily, even infecting the operating system). The production of special antivirus software has become an industry, and a number of exaggerated media reports have caused outbreaks of near hysteria among users. Many lusers tend to blame *everything* that doesn't work as they had expected on virus attacks. Accordingly, this sense of "virus" has passed into popular usage where it is often incorrectly used for other types of malware such as worms or Trojan horses.
See boot virus, phage. Compare back door. See also Unix conspiracy.
[The Jargon File]
(2003-06-20)
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