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


actively poisonous; intensely noxious: a virulent insect bite.
Medicine/Medical. highly infective; malignant or deadly.
Bacteriology. causing clinical symptoms.
violently or spitefully hostile.
intensely bitter, spiteful, or malicious: a virulent attack.

Origin of virulent

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

Related forms

Can be confused

violent virulent Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for virulent

British Dictionary definitions for virulent


/ (ˈvɪrʊlənt) /


  1. (of a microorganism) extremely infective
  2. (of a disease) having a rapid course and violent effect
extremely poisonous, injurious, etc
extremely bitter, hostile, etc

Derived Forms

virulently, adverb

Word Origin for virulent

C14: from Latin vīrulentus full of poison, from vīrus poison; see virus
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

Medicine definitions for virulent


[ vîryə-lənt, vîrə- ]


Extremely infectious, malignant, or poisonous. Used of a disease or toxin.
Capable of causing disease by breaking down protective mechanisms of the host. Used of a pathogen.
Intensely irritating, obnoxious, or harsh.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.