Virus

·vi Contagious or poisonous matter, as of specific ulcers, the bite of snakes, ·etc.;

— applied to organic poisons.

II. Virus ·vi Fig.: Any morbid corrupting quality in intellectual or moral conditions; something that poisons the mind or the soul; as, the virus of obscene books.

III. Virus ·vi The special contagion, inappreciable to the senses and acting in exceedingly minute quantities, by which a disease is introduced into the organism and maintained there.