mummer UK /ˈmʌm.ə(ɹ)/US /ˈmʌm.ɚ/noun 2verb 1forms 3 noun2 •A person who dons a disguising costume, as for a parade or a festival. •An actor in a pantomime; one who communicates entirely through gesture and facial expression.[To] perform as mummers, who act in relays of eight, at the worship of ancestors. — 1883 verb1 •Synonym of mum (“to act in pantomime or dumb show”).There is a general agreement that niggering [blackface performance] took over from mummering to keep up the old custom. — 1976 formsmummered · mummering · mummers