norovirus

noun

nor·​o·​vi·​rus ˈnȯr-ə-ˌvī-rəs 

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

Also, remember that norovirus is the most common cause of foodborne illness. —Katia Hetter, CNN Money, 20 Nov. 2025

State health officials say that although some wastewater sewer sheds have seen an increase in norovirus wastewater levels, those levels have been lower than previous peaks, like in early 2025. —Elaine Rojas-Castillo, CBS News, 20 Nov. 2025

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

Word History

Etymology

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

First Known Use

2002, in the meaning defined above

Rhymes for norovirus

• antivirus
• herpesvirus
• parvovirus
• reovirus
• retrovirus
• rhinovirus
• rotavirus
• adenovirus
• baculovirus
• coronavirus
• enterovirus
• poliovirus

Medical Definition

norovirus

noun

nor·​o·​virus ˌnȯr-ō-ˈvī-rəs 

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