virus: Meaning and Definition of

vi•rus

Pronunciation: (vī'rus), [key]
— pl. -rus•es.
  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. 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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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