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

A Manchester City supporter recently went viral as he celebrated a victory with an Arsenal water bottle, a nod to Arteta's side 'bottling' the title after three successive second-placed finishes.

From BBC • May 20, 2026

First identified in 1976 and believed to have originated in bats, Ebola is a deadly viral disease spread through direct contact with bodily fluids.

From Barron's • May 19, 2026

On a recent episode of What Next, host Mary Harris spoke to Rahman about how her life has changed since her detention, and how she’s trying to turn her viral moment into a movement.

From Slate • May 19, 2026

Ebola, a viral disease with no known cure, spreads when someone comes into contact with blood or body fluids from an infected person.

From The Wall Street Journal • May 18, 2026

The clip that had made the rounds on the Sunday morning news shows, and then went viral.

From "All American Boys" by Jason Reynolds