norovirus
noun
nor·o·virus
ˈnȯr-ə-ˌvī-rəs 
: any of a genus (Norovirus) of small, round, single-stranded RNA viruses that includes a single species (species Norwalk virus) 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
Cherie BlackNote: In people, noroviruses cause gastroenteritis marked chiefly by sudden onset diarrhea, vomiting, nausea, and abdominal cramps.
see norwalk virusExamples of norovirus in a Sentence
Recent Examples on the Web
In September, 71 passengers and one crew member fell ill due to a norovirus outbreak on Royal Caribbean’s Serenade of the Seas.
—Colson Thayer, PEOPLE, 23 Oct. 2025
Nearly 80 people got sick in a norovirus outbreak on an Oceania Cruises ship.
—Nathan Diller, USA Today, 22 Oct. 2025
In fact, this is the 14th norovirus outbreak so far in 2025 aboard a cruise ship within the Vessel Sanitation Program’s jurisdiction.3
That’s because the virus is highly contagious.
—Jenna Anderson, Health, 4 Oct. 2025
The Royal Caribbean cruise ship facing a norovirus outbreak while at sea docked at PortMiami early Thursday morning, concluding a 13-night voyage.
—Miami Herald, 3 Oct. 2025
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Colson Thayer, PEOPLE, 23 Oct. 2025
Nearly 80 people got sick in a norovirus outbreak on an Oceania Cruises ship.
—Nathan Diller, USA Today, 22 Oct. 2025
In fact, this is the 14th norovirus outbreak so far in 2025 aboard a cruise ship within the Vessel Sanitation Program’s jurisdiction.3
That’s because the virus is highly contagious.
—Jenna Anderson, Health, 4 Oct. 2025
The Royal Caribbean cruise ship facing a norovirus outbreak while at sea docked at PortMiami early Thursday morning, concluding a 13-night voyage.
—Miami Herald, 3 Oct. 2025
See All Example Sentences for norovirus
Cite this Entry
“Norovirus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/norovirus. Accessed 30 Oct. 2025.
Copy CitationMedical Definition
norovirus
noun
nor·o·virus
ˌnȯr-ō-ˈvī-rəs
1
capitalized
: a genus of small, round, single-stranded, highly infectious RNA viruses that includes a single species (species Norwalk virus) with various strains causing gastroenteritis in people and animals (such as cows and dogs)
2
: any virus of the genus Norovirus
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, The Seattle Post-Intelligencer
Cherie Black, The Seattle Post-IntelligencerNote: In people, noroviruses cause gastroenteritis marked chiefly by sudden onset, diarrhea, vomiting, nausea, and abdominal cramps.
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