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 of virulent

• 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

Further tests showed that the thick sticky coating made these bacteria more virulent than the normal-looking bacteria from the first urine sample. — Beth Mole, ArsTechnica, 23 July 2026

That small but extremely virulent fire killed 13 people, including several foreigners, in one of Spain’s deadliest wildfires. — ABC News, 22 July 2026

But even this hostile move did not prepare the DSA’s older membership for the virulent anti-Semitism that would pour forth from the group after the worst mass murder of Jews since the Holocaust. — James Kirchick, The Atlantic, 21 July 2026

Legionella, the bacteria that causes the virulent form of pneumonia known as Legionnaires’ disease, has been detected in a cooling tower at the Metropolitan Museum of Art on New York’s Upper East Side. — News Desk, Artforum, 15 July 2026

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