viral

American  

[vahy-ruhl] / ˈvaɪ rəl /

adjective

1. of, relating to, or caused by a virus.

2. pertaining to or involving the spreading of information and opinions about a product or service from person to person, especially on the internet or in emails.

   a clever viral ad.

3. becoming very popular by circulating quickly from person to person, especially through the internet.

   the most memorable viral videos;

   This book is already viral two weeks before its official publication date.

4. pertaining to a computer virus.

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idioms

1. go viral, to spread rapidly via the internet, email, or other media.

   Footage of the candidate's off-color remarks went viral within minutes.

viral British  

/ ˈvaɪrəl /

adjective

1. of, relating to, or caused by a virus

2. (of a video, image, story, etc) spread quickly and widely among internet users via social networking sites, e-mail, etc

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Other Word Forms

• antiviral adjective

Etymology

Origin of viral

First recorded in 1935–40; vir(us) + -al ¹

Explanation

If you go to work when you're sick, your co-workers will be hoping that whatever you've got isn't viral. Viral describes a disease caused by a virus, and viruses are usually infectious. Infections and other kinds of diseases can be classified as viral by a doctor, which means they're caused by viruses, specific kinds of microorganisms. Because of the speedy way that viral infections can spread, the meaning has grown to include the spread of ideas or information, often on the Internet. Viral videos are short online films that become incredibly popular very quickly, as people share them with each other and they spread like a virus.

Example Sentences

The missive came after her viral appearance alongside Carpenter during the weekend's headline set at the festival in the California desert.

From Barron's • Apr. 21, 2026

Meme stocks are darlings of retail traders and go viral on social media.

From MarketWatch • Apr. 21, 2026

Wearing outfits like her viral cheetah-print ensemble, Rinna skyrocketed to fan-favorite status during her tenure as a traitor.

From Los Angeles Times • Apr. 18, 2026

Anthropic is the maker of popular chatbot Claude and the viral coding app, Claude Code.

From The Wall Street Journal • Apr. 16, 2026

“No. But it’s never been this specifically viral before.”

From "Here to Stay" by Sara Farizan