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

See Examples For:

viral

The clip went viral, in part because the mistake was so specifically inhuman.

From Salon ● Oct. 11, 2026

The Cockroach party started as a viral online movement in response to the chief justice’s comments comparing unemployed young people to cockroaches.

From The Wall Street Journal ● Oct. 10, 2026

New fantasy rom-com Wicker, starring Olivia Colman and Alexander Skarsgård, has sparked a flood of viral memes and tongue-in-cheek jokes on social media ahead of its cinema release.

From BBC ● Oct. 9, 2026

Over the years, the magazine has ranked everything from Super Bowl halftime shows and horrible wedding songs to pre-YouTube viral hits and Declaration of Independence signatures.

From Slate ● Oct. 9, 2026

His most troubling conditions were a strangely recurrent viral pneumonia, chronic sinusitis, and the ulcerative colitis that had laid him low the weekend before his scheduled testimony against Oppenheimer.

From "Big Science" by Michael Hiltzik