norovirus

noun

nor·​o·​vi·​rus ˈnȯr-ə-ˌvī-rəs How to pronounce norovirus (audio)
plural noroviruses
: any of a genus (Norovirus) of small, round, single-stranded RNA viruses that includes a single species (N. norwalkense) with various strains causing gastroenteritis in people and animals (such as cows, pigs, and dogs)
People spread the virus by eating food or drinking liquids that are contaminated with norovirus, touching surfaces or objects contaminated with norovirus and then touching their mouth or having direct contact with another person who is infected.Cherie Black

Note: In people, noroviruses cause gastroenteritis marked chiefly by sudden onset diarrhea, vomiting, nausea, and abdominal cramps.

see norwalk virus

Examples of norovirus 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.
Here's what to know about the norovirus outbreak. Kristin Scharkey, USA Today, 1 June 2026 Fox News Digital also recently reported on a norovirus outbreak aboard the Caribbean Princess that sickened more than 100 passengers and crew members. Kelly McGreal, FOXNews.com, 17 May 2026 In fact, many within the industry still expect a record number of people worldwide to take cruises this year despite three passengers aboard the MV Hondius dying from hantavirus after the ship stopped in Argentina and a recent norovirus outbreak aboard a British ship docked in Bordeaux, France. ABC News, 16 May 2026 As summer approaches and the cruise season ramps up, travelers ready to set sail may feel uneasy due to recent hantavirus and norovirus outbreaks on cruise ships. Sukhman Rekhi, Verywell Health, 15 May 2026 See All Example Sentences for norovirus

Word History

Etymology

New Latin, from English Norwalk virus + New Latin -o- + virus

First Known Use

2002, in the meaning defined above

Time Traveler
The first known use of norovirus was in 2002

Browse Nearby Words

Cite this Entry

“Norovirus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/norovirus. Accessed 5 Jun. 2026.

Medical Definition

norovirus

noun
nor·​o·​virus ˌnȯr-ō-ˈvī-rəs How to pronounce norovirus (audio)
1
Norovirus : a genus of caliciviruses that includes a single species (Norovirus norwalkense) with various strains causing gastroenteritis in people and animals (such as cows and dogs)
2
: any virus of the genus Norovirus
Norovirus can be transmitted person-to-person (via the fecal-oral route) and spread through contaminated airborne droplets, food, water, environmental surfaces, and fomites.The Journal of the American Medical Association

Note: In people, noroviruses cause gastroenteritis marked chiefly by sudden onset, diarrhea, vomiting, nausea, and abdominal cramps.

see norwalk virus
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