D defs.my
Entry 1 sense Webster, 1913

Mumm

/mŭm/ · IPA /mˈʌm/
01 v. i. To sport or make diversion in a mask or disguise; to mask.
imp. & p. p. Mummed; p. pr. & vb. n. Mumming
  1. 1.
    To sport or make diversion in a mask or disguise; to mask.
    “With mumming and with masking all around.” Spenser.