COVID-19

noun

ˈkō-vid-nīn-ˈtēn 

variants or COVID

ˈkō-vid 

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

That memo also outlined planned agency changes in handling COVID-19 and certain other vaccines and said that FDA staff who disagreed should resign. —Michael Kaplan, CBS News, 7 Dec. 2025

Already, some states have responded to CDC’s decision to no longer recommend an annual COVID-19 vaccine by recommending it in their states and supporting insurance coverage for it as well. —Alice Park, Time, 6 Dec. 2025

Densley said the decline may also be influenced by falling homicide and violent-crime rates nationwide after COVID-19-era spikes. —Michael Dorgan, FOXNews.com, 6 Dec. 2025

But again, managing a side hustle on top of a demanding full-time job, was not only hard financially, but also mentally, as she was left with post-traumatic stress disorder (PTSD) from working as a bedside nurse during the COVID-19 pandemic. —Jasmine Laws, MSNBC Newsweek, 6 Dec. 2025

After dropping during the COVID-19 pandemic, researchers say, congestion has equaled — and, in many places, surpassed — pre-pandemic levels. —Joel Rose, NPR, 5 Dec. 2025

Cases dropped during the first year of the COVID-19 pandemic and then rebounded in 2021. —Mary Kekatos, ABC News, 5 Dec. 2025

Jeff Reitz, of Huntington Beach, set a 2,995 consecutive day streak of visiting Disneyland that ended with the yearlong COVID-19 closure of the park. —Brady MacDonald, Oc Register, 5 Dec. 2025

The rapid development of the COVID-19 vaccine in 2020 is one of many examples of how artificial intelligence has been a massive game-changer. —U T Editorial Board, San Diego Union-Tribune, 5 Dec. 2025

Word History

Etymology

coronavirus disease 2019

First Known Use

2020, in the meaning defined at sense 1

Kids Definition

COVID-19

noun

ˈkō-vid-nīn-ˈtēn 

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

ˈkō-vid-nīn-ˈtēn 

variants or COVID

ˈkō-vid 

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