Rift Valley fever

noun

: an acute, usually epizootic, mosquito-borne disease of domestic animals chiefly of eastern and southern Africa that is caused by a bunyavirus (Phlebovirus riftense), is marked especially by fever, abortion, and death of newborns, and is sometimes transmitted to humans usually in a milder form marked by flu-like symptoms

Examples of Rift Valley fever in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Ebola and rabies, anthrax and smallpox, Rift Valley fever and monkeypox. — Helen Branswell, STAT, 21 Sep. 2022 The goal of this five-year, multidisciplinary project is to examine, for the first time, exactly how climate affects Rift Valley fever in southern Africa. — Lois Parshley, Scientific American, 1 May 2018 In 2000, Saudi Arabia banned livestock export from Somalia because of the outbreak of Rift Valley fever. — Abdullahi Yussuf, Quartz Africa, 28 July 2020 Jamestown Canyon virus accumulates genetic changes 10 to 100 times more slowly per calendar year than dengue, Rift Valley fever or chikungunya. — John Drake, Forbes.com, 4 July 2026 Mosquitoes carry many threatening diseases, like chikungunya, dengue, lymphatic filariasis, Rift Valley fever, Yellow fever, Zika, malaria, Japanese encephalitis and West Nile fever, WHO reports. — Clare Mulroy, USA TODAY, 2 Feb. 2023

Word History

Etymology

(Great) Rift Valley, Africa

First Known Use

circa 1931, in the meaning defined above

Time Traveler
The first known use of Rift Valley fever was circa 1931

Rhymes for Rift Valley fever

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rift valley
Rift Valley fever
rig
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Cite this Entry

“Rift Valley fever.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Rift%20Valley%20fever. Accessed 7 Jul. 2026.

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Medical Definition

Rift Valley fever

noun
Rift Val·​ley fever ˈrift-ˌval-ē- How to pronounce Rift Valley fever (audio)
: an acute usually epizootic mosquito-borne disease of domestic animals (such as sheep and cattle) chiefly of eastern and southern Africa that is caused by a bunyavirus (Phlebovirus riftense), is marked especially by fever, abortion, death of newborns, diarrhea, and jaundice, and is sometimes transmitted to humans usually in a milder form marked by flu-like symptoms

More from Merriam-Webster on Rift Valley fever

Britannica.com: Encyclopedia article about Rift Valley fever

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