variants or COVID or Covid or Covid-19 or less commonly covid or covid-19
1
: a mild to severe respiratory illness that is caused by a coronavirus (Betacoronavirus pandemicum), is transmitted chiefly by contact with infectious material (such as respiratory droplets), and is characterized especially by fever, cough, loss of taste or smell, and shortness of breath and may progress to pneumonia and respiratory failure

Note: While fever, cough, loss of taste or smell, and shortness of breath are common symptoms of COVID-19, other symptoms may include fatigue, chills, body aches, headache, sore throat, runny nose, nausea, vomiting, or diarrhea. COVID-19 was first identified in Wuhan, China in December 2019.

Individuals with compromised immune systems, whether because of immunodeficiency or immunosuppressive therapy, are among those most susceptible to COVID-19.Edward P. K. Parker et al.
Many people who get tested regularly for COVID-19 … test positive despite reporting no symptoms at all. But such asymptomatic infections, which can also occur with other kinds of viruses, are difficult to track, since you may never know if you had one.Danielle Echeverria
But, now more than ever, we must remember that COVID is not just a personal threat but a community one. For older and immunocompromised people, the risks are still significant. For example, people over 50 account for 93 percent of COVID-related deaths in the U.S. …Yasmin Tayag
The federal government dramatically expanded the role that pharmacies play in U.S. health care, positioning them at the center of the national vaccination campaign against Covid. Two out of every 3 Covid shots have been administered by pharmacies … according to the National Association of Chain Drug Stores.Spencer Kimball
After the Memorial Day and Fourth of July weekends, cases of Covid-19 surged around the country after people held family gatherings or congregated in large groups.Tara Parker-Pope

called also coronavirus, coronavirus disease, coronavirus disease 2019, CV-19, CV19

see long covid
2
: the strain of the coronavirus (Betacoronavirus pandemicum) that causes COVID-19 : sars-cov-2
The goal of the vaccine is to trick cells to produce antibodies against COVID-19's surface protein, thereby eliminating the virus with the body's own immune system.Miriam Fauzia
A weak immune system enables COVID-19 to remain in the body longer, copy itself and continually change in ways that flout existing treatment …Dennis Thompson

Examples of COVID-19 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.
Aside from some quiet complaints about the NCAA’s COVID-19 protocols for people sitting around the court, no one offered anything other than positive reviews. Mac Engel march 31, Fort Worth Star-Telegram, 31 Mar. 2026 The rise can be attributed to a number of factors, with some research pointing to a drop-off in stimulus funds after COVID-19 as one of the catalysts. Mary Cunningham, CBS News, 30 Mar. 2026 Shortness of breath or difficulty breathing is also more often a sign of COVID-19 than the flu. Mary Walrath-Holdridge, USA Today, 30 Mar. 2026 Immigration court proceedings all over the country went virtual with the onset of the COVID-19 pandemic in 2020. Caroline Kubzansky, Chicago Tribune, 30 Mar. 2026 As the scouts tell it, MLB and teams used the COVID-19 pandemic as an opportunity to cull the herd of older scouts. Michael McCann, Sportico.com, 30 Mar. 2026 That figure marks a significant drop from a recent peak attained in 2023, but borrowing costs remain well above a 0% rate established at the outset of the COVID-19 pandemic. Max Zahn, ABC News, 30 Mar. 2026 For a brief time during the height of the COVID-19 pandemic when restaurants were shut down all over town, Mignonette was able to pivot and transform into an Italian takeout place, with great success. Madeleine Marr, Miami Herald, 30 Mar. 2026 For several years, the 32-year-old left the food industry to work in the corporate world until she was laid off during the COVID-19 pandemic. Olivia Wakim, AJC.com, 29 Mar. 2026

Word History

Etymology

coronavirus disease 2019

First Known Use

2020, in the meaning defined at sense 1

Time Traveler
The first known use of COVID-19 was in 2020

Browse Nearby Words

Cite this Entry

“COVID-19.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/COVID-19. Accessed 6 Apr. 2026.

Kids Definition

COVID-19

noun
variants also COVID
ˈkō-vid
: a mild to serious illness that is caused by a coronavirus and is marked especially by fever, cough, loss of taste or smell, and shortness of breath

Medical Definition

COVID-19

noun
variants or COVID or Covid or Covid-19 also covid or covid-19
1
: a mild to severe respiratory illness that is caused by a coronavirus (Betacoronavirus pandemicum), is transmitted chiefly by contact with infectious material (such as respiratory droplets), and is characterized especially by fever, cough, loss of taste or smell, and shortness of breath and may progress to pneumonia and respiratory failure

Note: While fever, cough, loss of taste or smell, and shortness of breath are common symptoms of COVID-19, other symptoms may include fatigue, chills, body aches, headache, sore throat, runny nose, nausea, vomiting, or diarrhea. COVID-19 was first identified in Wuhan, China in December 2019.

Individuals with compromised immune systems, whether because of immunodeficiency or immunosuppressive therapy, are among those most susceptible to COVID-19.Edward P. K. Parker et al., The Lancet Global Health
Non-pharmaceutical measures including physical distancing, proper use of masks, … and quarantines have been imposed to delay the spread of Covid-19.Ikbel Hadj Hassine, Reviews in Medical Virology
The prevalence of COVID-19 in children is low (between 0.8% and 3.3%) and most children only display mild physical symptoms or are asymptomatic.Ulrike Ravens-Sieberer et al., European Child & Adolescent Psychiatry

called also coronavirus, coronavirus disease, coronavirus disease 2019, CV-19, CV19

see long covid
2
: the strain of the coronavirus (Betacoronavirus pandemicum) that causes COVID-19 : sars-cov-2
Over the past 10 to 20 years, we have developed a series of technologies that are designed to make antibodies against many disease targets, including viruses. These technologies were used by our scientists to develop a cocktail of three antibodies to bind and block the GP [=glycoprotein] protein of Ebola. … And now we have used the same technologies to rapidly make an antibody cocktail … that binds and blocks the spike protein of Covid-19.George Yancopoulos, The New York Times
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