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]

The Collaborative International Dictionary of English. 2000.

Look at other dictionaries:

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  • bacteriophages — (= phages) Viruses that infect bacteria. The bacteriophages that attack Escherichia coli are termed coliphages, examples of these are lambda phage and the T even phages, T2, T4 and T6. Basically, phages consist of a protein coat or capsid… …   Dictionary of molecular biology

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  • bacteriophages — n. virus that causes infection in bacteria …   English contemporary dictionary

  • virulent bacteriophages — (vir u lent bak te re o feījs ) Bacteriophages that lyse their host cells during the reproductive cycle …   Dictionary of microbiology

  • temperate phages — Bacteriophages that can infect bacteria and establish a lysogenic relationship rather than immediately lysing their hosts …   Dictionary of microbiology

  • Phagothérapie — La phagothérapie est l utilisation de bactériophages (ou phages) lytiques afin de traiter certaines maladies infectieuses d’origine bactérienne. Ce traitement a été largement utilisé dans le monde avant la découverte des antibiotiques. Bien… …   Wikipédia en Français

  • Stefan Ślopek — Infobox Scientist name = Stefan Ślopek image width = 250px caption = Stefan Ślopek birth date = birth date|1914|12|01 birth place = Skawa, Austria Hungary death date = death date and age|1995|8|22|1914|12|01|mf=y death place = Wrocław, Poland… …   Wikipedia

  • Bacteriophage — Bactériophage Un bactériophage (ou phage) est un virus n infectant que des bactéries. En grec, phageton signifie nourriture/consommation. On les appelle également virus bactériens. Ce sont des outils fondamentaux de recherche et d étude en… …   Wikipédia en Français

  • Bactériophage — Cet article possède un paronyme, voir : FAGE. Un bactériophage (ou phage) est un virus n infectant que des bactéries. En grec, phageton signifie nourriture/consommation. On les appelle également virus bactériens. Ce sont des outils… …   Wikipédia en Français

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