virus Look up virus at Dictionary.com
1392, "venomous substance," from L. virus "poison, sap of plants, slimy liquid," probably from PIE base *weis- "to melt away, to flow," used of foul or malodorous fluids (cf. Skt. visam "poison," visah "poisonous;" Avestan vish- "poison;" L. viscum "sticky substance, birdlime;" Gk. ios "poison," ixos "mistletoe, birdlime; O.C.S. višnja "cherry;" O.Ir. fi "poison;" Welsh gwy "fluid, water," gwyar "blood"). Main modern meaning "agent that causes infectious disease" first recorded 1728. The computer sense is from 1972. Adjective form viral was coined 1948.