• 1. In medieval and early modern times, one of a band of performerswho would dress in masks and fantastic costumes and visit from door to door,especially at Christmas. They were also known as guisers or guisards.

    2. by extension, a contemptuous name for an actor.

    We call strolling acting 'mumming', and the actors 'mummers'.All spouting is mumming.
    HENRY MAYHEW: London Labour (1861)