fla·​vi·​vi·​rus ˈflā-vi-ˌvī-rəs How to pronounce flavivirus (audio)
: any of a family (Flaviviridae and especially genus Flavivirus) of single-stranded RNA viruses transmitted especially by ticks and mosquitoes and including the causative agents of dengue, hepatitis C, hog cholera, Saint Louis encephalitis, West Nile virus, and yellow fever

Examples of flavivirus in a Sentence

Recent Examples on the Web The most common in the U.S. is West Nile Virus, a potentially fatal neurologic disease caused by a flavivirus carried by mosquitoes. Byerin Prater, Fortune Well, 1 July 2023 The Zika virus is a flavivirus closely related to notorious pathogens including dengue, yellow fever, Japanese encephalitis, and West Nile virus. Christie Wilcox, Discover Magazine, 1 Feb. 2016 Zika virus is a flavivirus, part of the same family as yellow fever, West Nile, chikungunya and dengue fever. Cnn Editorial Research, CNN, 27 May 2021 Yellow fever, a flavivirus, has parallels to SARS-CoV-2, the novel coronavirus that causes COVID. Alicia Ault, Smithsonian Magazine, 2 June 2020 Zika, a flavivirus that falls under the same category as West Nile, causes only mild symptoms — at worst — in most people. Rose Minutaglio, PEOPLE.com, 3 July 2019 However, the study said technical obstacles will delay making vaccines against Zika and other related viruses, called flaviviruses. Bradley J. Fikes, sandiegouniontribune.com, 4 Oct. 2017 Upon entering a human body, had the long-unheralded flavivirus always had the power to attack any developing brain tissue inside its human host and wreak a special kind of havoc? Melissa Healy, latimes.com, 28 Sep. 2017 Also, the disease belongs to a family of viruses known as flaviviruses, which scientists have been battling for more than a century. Katie Thomas, New York Times, 19 Nov. 2016 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'flavivirus.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


New Latin, from Latin flavus yellow + New Latin -i- + virus — more at virus

First Known Use

1974, in the meaning defined above

Time Traveler
The first known use of flavivirus was in 1974

Dictionary Entries Near flavivirus

Cite this Entry

“Flavivirus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flavivirus. Accessed 26 Sep. 2023.

Medical Definition


fla·​vi·​vi·​rus ˈflā-vi-ˌvī-rəs How to pronounce flavivirus (audio)
capitalized : a genus of the family Flaviviridae of single-stranded RNA viruses that are transmitted by arthropod vectors and especially by ticks and mosquitoes and that include the causative agents of dengue, Japanese B encephalitis, Saint Louis encephalitis, West Nile fever, and yellow fever
: any virus of the genus Flavivirus or the family Flaviviridae

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