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Synonyms

virulent

American  
[vir-yuh-luhnt, vir-uh-] / ˈvɪr yə lənt, ˈvɪr ə- /

adjective

  1. actively poisonous; intensely noxious.

    a virulent insect bite.
    Synonyms:
    venomous
    Antonyms:
    harmless

  2. Medicine/Medical. highly infective; malignant or deadly.

  3. Bacteriology. causing clinical symptoms.

  4. violently or spitefully hostile.

  5. intensely bitter, spiteful, or malicious.

    a virulent attack.
    Synonyms:
    acerbic, vicious
virulent British  
/ ˈvɪrʊlənt /

adjective

    1. (of a microorganism) extremely infective

    2. (of a disease) having a rapid course and violent effect

  2. extremely poisonous, injurious, etc

  3. extremely bitter, hostile, etc

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • hypervirulent adjective
  • hypervirulently adverb
  • nonvirulent adjective
  • nonvirulently adverb
  • supervirulent adjective
  • supervirulently adverb
  • unvirulent adjective
  • unvirulently adverb
  • virulently adverb

Etymology

Origin of virulent

1350–1400; Middle English verulent < Latin vīrulentus, equivalent to vīr ( us ) poison ( virus ) + -ulentus -ulent

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

We must confront the causal factors of antisemitism honestly and address antisemitism where it is most common and most virulent.

From Los Angeles Times • Mar. 24, 2026

"Fusarium wilt -- also known as Panama disease -- is a destructive soil-borne disease which impacts farmed Cavendish bananas worldwide through its virulent Race 4 strains," Dr. Chen said.

From Science Daily • Feb. 19, 2026

But time travel is an imperfect science, and the technician overseeing the process is delirious from a virulent new strain of flu, so Kivrin is accidentally dropped into 1348, the year of the Black Death.

From The Wall Street Journal • Feb. 17, 2026

It said there had been outbreaks on wards and the dominant strain was "particularly virulent".

From BBC • Dec. 9, 2025

As a result, a less lethal myxo virus spreads baby viruses to more rabbits than did the original, highly virulent myxo.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.