viral

The word “viral” means relating to, or caused by, a virus. In plain terms, either "caused by a virus" or, more commonly now, "spreading incredibly fast online.".

“Viral” is pronounced VEYE-ruhl (/ˈvaɪɹəl/ in IPA).

Here is “viral” used in a sentence: “The doctor confirmed it was a viral infection, not bacterial.”

Words with a similar meaning to “viral” include virous.

Depending on how it is used, “viral” can be an adjective and a noun.

“Viral” is a fairly common word in modern English.

“Viral” has 3 distinct senses listed in this dictionary. The most common is: relating to, or caused by, a virus.

A viral infection is caused by a virus, while a bacterial infection is caused by bacteria — two different kinds of microorganisms. The distinction matters for treatment, because antibiotics can treat bacterial infections but are ineffective against viral ones.

No. The original sense of "viral" is medical — relating to or caused by a virus, as in "a viral infection" — and the online sense of spreading rapidly is a figurative extension of it. Context makes clear which sense is meant.

Viral marketing is a strategy that designs content people will want to share, so the message spreads rapidly from person to person online rather than relying on paid placement alone. The name borrows the sense of "viral" that describes fast, self-multiplying spread.