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

The incubation period for pneumonic plague — the disease's most virulent form — can be as short as 24 hours, according to the WHO. — ABC News, 7 Oct. 2026

Pneumonic plague is a virulent form of plague that can be passed from human to human. — Don Sweeney, Sacbee.com, 6 Oct. 2026

The virus is spread through the air when an infected person coughs, sneezes and breathes and can remain virulent for up to two hours. — Lucia Cheng, Des Moines Register, 24 Aug. 2026

The isotopes that make up radiopharmaceuticals are just as virulent as the beam radiation patients have begrudgingly tolerated for decades. — Allison Deangelis, STAT, 10 Aug. 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