Viral infections are any illness you get from a virus (a small germ that uses your cells to reproduce). Examples include the flu, colds, COVID-19 and HPV. VIRAL definition: 1. caused by a virus: 2. used to describe something that quickly becomes very popular or well…. Learn more. The meaning of VIRAL is of, relating to, or caused by a virus. How to use viral in a sentence. The word Viral means "relating to viruses " (small infectious agents). It may also refer to: Memetic behavior likened that of a virus, for example: 1. Of, relating to, or caused by a virus. 2. Of or relating to the rapid propagation of information, ideas, or trends by means of social networks rather than conventional mass media: viral marketing. A viral film clip, story, or message is one that spreads quickly because people share it on social media and send it to each other. used to describe a piece of information, a video, an image, etc. that is sent rapidly over the internet and seen by large numbers of people within a short time. Within 24 hours, the video went viral on YouTube and Facebook. Definition of viral adjective in Oxford Advanced Learner's Dictionary. Sep 24, 2025 · Yet again, something dreadful and new which he doesn't understand is going viral. Today's fad is, you paint a black vertical rectangle on the wall, or on a mirror, or over the top of a picture. 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. becoming very popular by circulating quickly from person to person, especially through the internet. Master the word "VIRAL" in English: definitions, translations, synonyms, pronunciations, examples, and grammar insights - all in one complete resource.