The definition of a virus is an extremely tiny parasite that can only reproduce if it is within a living being, or anything that corrupts something else.
(noun)See virus in Webster's New World College Dictionary
noun
Origin: L, a slimy liquid, poison < IE base *weis-, to flow (used of foul or malodorous fluids) > ooze, weasel, Gr ios, poison
See virus in American Heritage Dictionary 4
noun pl. vi·rus·es
Origin:
Origin: Latin vīrus, poison
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