1. 恶毒;狠毒;敌意
Virulence is great bitterness and hostility.

2. 毒力;毒性;致命性
The virulence of a disease or poison is its ability to harm or kill people or animals.

1. extreme hostility

e.g. the virulence of the malicious old man

Synonym: virulency

2. extreme harmfulness (as the capacity of a microorganism to cause disease)

e.g. the virulence of the plague

Synonym: virulency