Definition of virulent in English:

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Pronunciation: /ˈvɪrʊl(ə)nt/
Pronunciation: /ˈvɪrjʊl(ə)nt/


1(Of a disease or poison) extremely severe or harmful in its effects: a virulent strain of influenza the poison is so virulent that it kills a fish instantly
More example sentences
  • Mark Oliver Everett is what epidemiologists and Dustin Hoffman call a hot spot, a highly contagious carrier of an extremely virulent disease who infects anyone who crosses his path.
  • And on the nursing front, Alwin notes that there's been an outbreak of atypical pneumonias in Asia, possibly harbingers of a more virulent flu strain to come.
  • There is no question that the outbreak of SARS (severe acute respiratory syndrome) has focused the world's attention on the dangers of how easily a virulent disease can spread around the globe.
poisonous, toxic, venomous, noxious, deadly, lethal, fatal, mortal, terminal, death-dealing, life-threatening, dangerous, harmful, injurious, pernicious, damaging, destructive, unsafe;
contaminating, polluting
literary deathly, nocuous, mephitic
archaic baneful
highly infectious, highly infective, highly contagious, infectious, infective, contagious, rapidly spreading, communicable, transmittable, transmissible, spreading, malignant, uncontrollable, pernicious, pestilential;
severe, extreme, violent, dangerous, harmful, lethal, life-threatening
informal catching
literary pestiferous
1.1(Of a pathogen, especially a virus) highly infective: Staphylococcus aureus is a common organism whose virulent strains are causing problems
More example sentences
  • The paper reflects a major step forward in the study of how some of the world's most virulent viruses, such as West Nile, SARS, Ebola and Hepatitis C interact with their hosts.
  • Dr. Mackinnon said: ‘How does immune selection create more virulent pathogens?’
  • Labs are rated on a scale of one to four, four being the highest level of containment where the nastiest, most virulent pathogens are handled.
2Bitterly hostile: a virulent attack on liberalism
More example sentences
  • It becomes more obvious that the options the two Parties present to the electorate, offer the unenviable choice between a raging toothache, a migraine, and a virulent attack of the Farmer's.
  • Over the years, founder Ted Byfield has been particularly virulent in his attacks on the mindset that is increasingly reliant on government handouts and regulation.
  • When word came that Iron Mike had been floored by a virulent attack of the sniffles, his disconsolate well-wishers had to shuffle off without meeting their thick-necked hero.
vitriolic, malicious, malevolent, malignant, malign, evil-intentioned, resentful, hostile, spiteful, venomous, vicious, vindictive, bitter, rancorous, acrimonious, mordant, astringent, incisive, cutting, biting, scathing, caustic, stinging, blistering, searing, withering, abusive, mean, nasty, aggressive, savage, harsh, devastating
informal bitchy, catty
literary malefic, maleficent



Pronunciation: /ˈvɪrʊl(ə)ntli/
Pronunciation: /ˈvɪrjʊl(ə)ntli/
Example sentences
  • The disease, which causes painful, ulcerating blisters on the mouth, feet, and udders, is virulently contagious, and once introduced can quickly infect an entire herd.
  • But the Prince's repeated use of the word ‘epidemic’ implied, irresponsibly, that these conditions are virulently contagious.
  • They fell foul of the powers that be, however, for their virulently outspoken stance in opposition to The Falklands War (where, like the Gulf War, hardly any protest was made).


Late Middle English (originally describing a poisoned wound): from Latin virulentus, from virus 'poison' (see virus).

  • virus from Late Middle English:

    A virus was originally the venom of a snake, and was an English borrowing of a Latin word meaning ‘slimy liquid’ or ‘poison’, that is also the source of virulent (Late Middle English). Early medical practitioners used the word for a substance produced in the body as the result of disease. The modern meaning dates from the late 19th century. The computer virus dates from the early 1970s.

For editors and proofreaders

Line breaks: viru|lent

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