| 单词 | virus |
| 释义 | virus[ vahy-ruhs ] / ˈvaɪ rəs / SEE SYNONYMS FOR virus ON THESAURUS.COM noun, plural vi·rus·es.an ultramicroscopic (20 to 300 nanometers 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. Informal. a viral disease. a corrupting influence on morals or the intellect; poison. a segment of self-replicating code planted illegally in a computer program, often to damage or shut down a system or network. Origin of virusFirst recorded in 1590–1600; from Latin vīrus “slime, poison”; akin to Sanskrit viṣá-, Avestan viša-, Greek iós (from earlier wiós, from still earlier wisós ), all meaning “poison, venom” OTHER WORDS FROM virusvi·rus·like, adjectivean·ti·vi·rus, adjectiveDictionary.com UnabridgedBased on the Random House Unabridged Dictionary, © Random House, Inc. 2020 British Dictionary definitions for virusvirus / (ˈvaɪrəs) / noun plural -rusesany 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 informal a disease caused by a virus any corrupting or infecting influence 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 of virusvirus-like, adjectiveWord Origin for virusC16: from Latin: slime, poisonous liquid; related to Old English wāse marsh, Greek ios poison Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Cultural definitions for virus (1 of 3)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.”) notes for virusViruses cause many diseases. (See viral infection.) Cultural definitions for virus (2 of 3)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.”) Cultural definitions for virus (3 of 3)virus See computer virus. The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. Medical definitions for virus (1 of 2)virus [ vī′rəs ] n. pl. vi•rus•esAny of a large group of submicroscopic agents that act as parasites and consist of a segment of DNA or RNA surrounded by a coat of protein. Because viruses are unable to replicate without a host cell, they are not considered living organisms in conventional taxonomic systems. Nonetheless, they are described as live when they are capable of replicating and causing disease. A disease caused by a virus. Medical definitions for virus (2 of 2)-virus suff.Genus of viruses:Influenzavirus. The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company. Scientific definitions for virusvirus [ vī′rəs ] Plural virusesAny 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. 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. Other words from virusviral adjectiveThe American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. |
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