virulent

adjective

vir·​u·​lent ˈvir-ə-lənt 

ˈvir-yə-

1

a

: marked by a rapid, severe, and destructive course

a virulent infection

b

: able to overcome bodily defensive mechanisms : markedly pathogenic

virulent bacteria

2

: extremely poisonous or venomous

3

: full of malice : malignant

virulent racists

4

: objectionably harsh or strong

virulent criticism

virulently adverb

Synonyms

• malicious
• vicious
• cruel
• hateful
• nasty

Examples of virulent in a Sentence

The country seemed to be returning to the virulent nationalism of its past.

the virulent look on her face warned me that she was about to say something unkind

Recent Examples on the Web

Viruses can mutate to escape from antibodies, but the mRNA vaccines are not causing the emergence of more virulent strains, likely for at least two reasons. —Deborah Fuller, CNN Money, 10 Sep. 2025

Our Lady of Perpetual Fortitude is run by the virulent and mischievous Monsignor Jefferson Wicks (Josh Brolin). —Esther Zuckerman, Time, 8 Sep. 2025

Viruses can mutate to escape from antibodies, but the mRNA vaccines are not causing the emergence of more virulent strains, likely for at least two reasons. —Deborah Fuller, The Conversation, 3 Sep. 2025

The researchers analyzed samples of coronary plaques–fatty buildups on artery walls–from heart patients and found that about 40% of them had virulent bacteria in them. —Alex Knapp, Forbes.com, 29 Aug. 2025

Word History

Etymology

Middle English, "discharging watery pus, purulent," borrowed from Latin vīrulentus "full of poison, venomous," from vīrus "venom, poisonous fluid" + -ulentus "having in quantity, full of" — more at virus

First Known Use

14th century, in the meaning defined at sense 1a

Phrases Containing virulent

• hyper-virulent

Rhymes for virulent

• avirulent

Kids Definition

virulent

adjective

vir·​u·​lent ˈvir-(y)ə-lənt 

1

a

: marked by a rapid, severe, and often deadly course

a virulent infection

b

: able to overcome or break down the defenses of the body

a virulent germ

2

: extremely poisonous : noxious

3

: full of hate : spiteful

virulently adverb

Medical Definition

virulent

adjective

vir·​u·​lent -lənt 

1

a

: marked by a rapid, severe, and malignant course

a virulent infection

b

: able to overcome bodily defense mechanisms

a virulent pathogen

2

: extremely poisonous or venomous : noxious