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.

---

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

---

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

That’s the question startups, investors and big corporations were asking after an internal dashboard at Meta Platforms went viral for ranking employees by their individual token usage and doling out flashy titles like “Token Legend.”

From The Wall Street Journal • Apr. 14, 2026

We do not know if any of the children were HIV-positive but this practice creates a clear risk of viral transmission.

From BBC • Apr. 13, 2026

Also read: The ‘smart money’ fled software stocks after Citrini’s viral AI doomsday report.

From MarketWatch • Apr. 13, 2026

I’d sit with my coffee and catch up: Duncan’s article had gone viral, Lisa wanted someone to review a draft, Sarah had been invited to give feedback to a new platform for writers.

From Slate • Apr. 12, 2026

It occurs to me how awful that nickname is: Calling your needy little sister something that’s one letter off from a viral infection that causes acute inflammation of the brain?

From "Odd One Out" by Nic Stone