Dictionary.net

extreme hostility; "the virulence of the malicious old man"

extreme hostility; "the virulence of the malicious old man"

The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host.

The state or quality of being very poisonous; extreme bitterness; malignity. Also, virulency.

The quality of being poisonous; the disease-producing power of a microorganism.

Malignant; poisonous.

That quality which renders a thing extremely active in doing injury; extreme bitterness or malignity.

Extreme poisonousness or acrimony.

The power possessed by organisms to produce disease in a living host, with the formation of poisonous substances. The variations in v. of an organism in different species of hosts are due to greater power to grow than to produce poisonous processes. [Lat.]

n. Quality of being virulent; injurious activity; poisonousness;—acrimony of temper; extreme bitterness or malignity;—rancour; venom.