Definition of viral in US English:



  • 1Of the nature of, caused by, or relating to a virus or viruses.

    • ‘Neither do attacks appear viral or worm-like in nature, as had been suspected.’
    • ‘It is a form of infection which is generally from the food passing through the bowels and can be bacterial or even viral.’
    • ‘It is difficult for non-medically trained people to know if their ailment is bacterial or viral.’
    • ‘Swabs taken into viral culture medium yielded herpes simplex virus type 2.’
    • ‘The complexities that surround the properties of viral bacteria are discussed with wonderful clarity.’
    • ‘There is no guaranteed way of preventing viral and bacterial infections.’
    • ‘There are a number of causes of meningitis, including viral and bacterial infections.’
    • ‘Many serious viral and bacterial infections can now be prevented or treated by vaccination or antibiotics.’
    • ‘Further tests should show whether the whale had any bacterial or viral infection.’
    • ‘Oral herpes is a viral infection that affects the mouth, throat, and parts of the face.’
    • ‘It is a sign of other problems in the body, and is usually caused by a viral or bacterial infection.’
    • ‘Symptoms and signs of influenza in children are not specific and can mimic a range of other common respiratory viral pathogens.’
    • ‘Such infections would include viral and intracellular bacterial infections.’
    • ‘The three most common types of conjunctivitis are: viral, allergic and bacterial.’
    • ‘Wild gorillas suffer a range of viral and bacterial illnesses as well as internal and external parasites.’
    • ‘Some doctors believe that pityriasis rosea is caused by a viral or bacterial infection.’
    • ‘Pieces of DNA are inserted into a bacterial or viral host in a form that replicates asexually.’
    • ‘The doctor checks other symptoms presented by the patient, to work out whether the tonsillitis is viral or bacterial.’
    • ‘Dogs can be a host to several bacterial and viral infections that you can contract such as ring worm.’
    • ‘A really complex microfluidic device ought to be able to synthesis a viral pathogen.’
  • 2Relating to or involving an image, video, piece of information, etc., that is circulated rapidly and widely from one Internet user to another.

    ‘a viral video ad’
    ‘the video went viral and was seen by millions’
    • ‘Using multimedia, his blog and the viral nature of the net, he's shown that one voice can echo around the world.’
    • ‘Weblogs are a viral medium of expression, spread by contact with webloggers.’
    • ‘In fact the email is not viral, but the product of an online marketing initiative run by the e-card company.’
    • ‘The resulting viral spread of hype ensured that their debut album became the fastest selling record in British history.’
    • ‘It's a shame really, because the viral nature of the webnetthingy could have one of two profound effects on politics.’


  • An image, video, advertisement, etc., that is circulated rapidly on the Internet.

    ‘the rise of virals in online marketing’
    • ‘There's currently lots of talk in the advertising biz about doing away with straight broadcasting messages and replacing them with virals or whatever.’
    • ‘The second most common virals today are emails.’
    • ‘The most frequent type of security breach was a result of virals coming from outside the enterprise.’
    • ‘Businesses are waking up to the need for this high level of protection, but are still being bombarded by virals.’
    • ‘As with all great virals, the story delivers a nice little twist at the end.’