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Meaning of VIRUS

Pronunciation:  'vIrus

WordNet Dictionary
 
 Definition: [n]  ultramicroscopic infectious agent that replicates itself only within cells of living hosts; many are pathogenic; a piece of nucleic acid (DNA or RNA) wrapped in a thin coat of protein
 
 Websites: 
 
 See Also: animal virus, bacteriophage, microorganism, phage, plant virus, slow virus, tumor virus

 

 

Products Dictionary
 
 Definition: 

Virus
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Webster's 1913 Dictionary
 
 Definition: 
\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.
 
Computing Dictionary
 
 Definition: 

(By analogy with biological viruses, via SF) A program or piece of code 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 a worm or Trojan horse.

See boot virus, phage. Compare back door. See also Unix conspiracy.

[Jargon File]

 
Medical Dictionary
 
 Definition: A simple pathogenic microorganism that invades living cells and uses cellular mechanisms to create multiple copies of itself.
 
Biology Dictionary
 
 Definition: 
  1. A noncellular biological entity that can reproduce only within a host cell. Viruses consist of nucleic acid covered by protein; some animal viruses are also surrounded by membrane. Inside the infected cell, the virus uses the synthetic capability of the host to produce progeny virus.
  2. A computer program designed to covertly infiltrate and usually damage a computer system, either by repeatedly copying itself so that it takes up needed memory or by erasing, modifying or damaging other files.
 
Glossary
 
 Definition: 
  1. An infectious particle composed of a protein capsule and a nucleic acid core, which is dependent on a host organism for replication. A double-stranded DNA copy of an RNA virus genome that is integrated into the host chromosome during lysogenic infection. (See Coat protein, DNA, Genome, Host, Nucleic acid, RNA, Tumor virus)
  2. A noncellular biological entity that can reproduce only within a host cell. Viruses consist of nucleic acid covered by protein; some animal viruses are also surrounded by membrane. Inside the infected cell, the virus uses the synthetic capability of the host to produce progeny virus.
 

 

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