Vī'rus, n.
n. [Lat., a slimy liquid, a poisonous liquid, poison.]
Sense 1. (Med.) (a.) Contagious or poisonous matter, as of specific ulcers, the bite of snakes, and the like;—applied to organic poisons. (b.) The special contagion of a disease.
“By it [virus] is understood a principle unknown in its nature, and inappreciable by the senses, which is the agent for the transmission of infectious diseases. Thus, we speak of the variolic, vaccine, and syphilitic viruses. Virus differs from venom in the latter being a secretion natural to certain animals, whilst the former is always the result of a morbid process,—a morbid poison.” Dunglison.
Sense 2. Hence, the spirit, aim, or drift of any thing injurious, especially any thing of a moral nature; as, the virus of party spirit.