viral >> ˈvʌɪr(ə)l
Definition: [adjective] of the nature of, caused by, or relating to a virus or viruses.
Example: a severe viral infection
Definition: [adjective] (of an image, video, piece of information, etc.) circulated rapidly and widely from one internet user to another.
Example: a viral ad campaign
Definition: [noun] an image, video, piece of information, etc. that is circulated rapidly and widely on the internet.
Example: the rise of virals in online marketing