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

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

This season's norovirus wave reached its highest ever percentage of positive test results for 2024-25 in the second week of this month. —Elizabeth B. Kim, The Enquirer, 2 July 2025

Several other countries also saw unusually large or shifted waves of norovirus this past year, after GII.17 surged to dominance. —Nicole Brown Chau, CBS News, 3 June 2025

Health officials say the outbreak is accompanied by rising infection rates for other viruses, including RSV, COVID-19 and the gastrointestinal bug norovirus. —Rebecca Morin, USA TODAY, 20 Feb. 2025

In previous years, the U.S. usually saw norovirus outbreaks increase around December. —Nicole Brown Chau, CBS News, 3 June 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

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

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

see norwalk virus