Virus

5 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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.) Contagious or poisonous matter, as of specific
        ulcers, the bite of snakes, etc.; -- applied to organic
        poisons. [Archaic]


        [1913 Webster +PJC]
  
     2. the causative agent of a disease, . [obsolescent]
        [PJC]
  
     3. any of numerous submicroscopic complex organic objects
        which have genetic material and may be considered as
        living organisms but have no proper cell membrane, and
        thus cannot by themselves perform metabolic processes,
        requiring entry into a host cell in order to multiply. The
        simplest viruses have no lipid envelope and may be
        considered as complex aggregates of molecules, sometimes
        only a nucleic acid (DNA or RNA) and a coat protein. They
        are sometimes viewed as being on the borderline between
        living and nonliving objects. They are smaller than living
        cells in size, usually between 20 and 300 nm; thus they
        pass through standard filters, and were previously
        referred to as {filterable virus}. The manifestations of
        disease caused by multiplication of viruses in cells may
        be due to destruction of the cells caused by subversion of
        the cellular metabolic processes by the virus, or by
        synthesis of a virus-specific toxin. Viruses may infect
        animals, plants, or microorganisms; those infecting
        bacteria are also called {bacteriophages}. Certain
        bacteriophages may be non-destructive and benign in the
        host; -- see {bacteriophage}.
        [1913 Webster +PJC]
  
     4. Fig.: Any morbid corrupting quality in intellectual or
        moral conditions; something that poisons the mind or the
        soul; as, the virus of obscene books.
        [1913 Webster]
  
     5. (Computers) a program or segment of program code that may
        make copies of itself (replicate), attach itself to other
        programs, and perform unwanted actions within a computer;
        also called {computer virus} or {virus program}. Such
        programs are almost always introduced into a computer
        without the knowledge or assent of its owner, and are
        often malicious, causing destructive actions such as
        erasing data on disk, but sometime only annoying, causing
        peculiar objects to appear on the display. The form of
        sociopathic mental disease that causes a programmer to
        write such a program has not yet been given a name.
        Compare {trojan horse[3]}.
        [PJC]

From WordNet (r) 2.0 [wn]:

  virus
       n 1: (virology) 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
       2: a harmful or corrupting agency; "bigotry is a virus that
          must not be allowed to spread"; "the virus of jealousy is
          latent in everyone"
       3: a software program capable of reproducing itself and usually
          capable of causing great harm to files or other programs
          on the same computer; "a true virus cannot spread to
          another computer without human assistance" [syn: {computer
          virus}]

From Moby Thesaurus II by Grady Ward, 1.0 [moby-thes]:

  120 Moby Thesaurus words for "virus":
     acaricide, adenovirus, aerial infection, aerobe, aerobic bacteria,
     aerobic organism, airborne infection, amoeba, anaerobe,
     anaerobic bacteria, anaerobic organism, anthelmintic, antibiotic,
     antiseptic, autotrophic organism, bacillus, bacteria, bacterium,
     bane, being, bug, bug bomb, carbamate insecticide, carrier,
     chemosterilant, chlorinated hydrocarbon insecticide, coccus,
     communicability, contact poison, contagion, contagiousness,
     contamination, corruption, creature, cryptogenic infection,
     defoliant, direct infection, disease-producing microorganism,
     disinfectant, droplet infection, dust infection, echovirus,
     enterovirus, epidemiology, eradicant, filterable virus, fumigant,
     fungicide, fungus, genetic individual, germ, germicide,
     gram-negative bacteria, gram-positive bacteria, hand infection,
     herbicide, heterotrophic organism, indirect infection, individual,
     infection, infectiousness, insect powder, insecticide,
     living being, living thing, microbe, microbicide, microorganism,
     miticide, mold, morphological individual, nonfilterable virus, ont,
     organic being, organic chlorine, organic phosphate insecticide,
     organism, organization, pathogen, pesticide,
     physiological individual, phytogenic infection, picornavirus,
     poison, primary infection, protozoa, protozoon, pyogenic infection,
     rat poison, reovirus, rhinovirus, rickettsia, roach paste,
     roach powder, rodenticide, secondary infection, spirillum,
     spirochete, spore, staphylococcus, stomach poison, streptococcus,
     subclinical infection, systemic, systemic insecticide, taint,
     toxic, toxicant, toxin, trypanosome, vector, venin, venom,
     vermicide, vibrio, waterborne infection, weed killer,
     zoogenic infection, zooid, zoon
  
  

From Jargon File (4.3.1, 29 Jun 2001) [jargon]:

  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 horse}s.
     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 hack}s). Many nasty viruses,
     written by particularly perversely minded {cracker}s, do irreversible
     damage, like nuking all the user's files.
  
     In the 1990s, viruses became a serious problem, especially among
     Windows 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
     {luser}s 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}.
  
  

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  virus
       
           (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}]
       
          (2003-06-20)