MUMM
Verb
mumm (third-person singular simple present mumms, present participle mumming, simple past and past participle mummed)
Archaic form of mum (“to act in pantomime or dumb show”).
Source: Wiktionary
Mumm, v. i. [imp. & p. p. Mummed; p. pr. & vb. n. Mumming.] Etym: [D.
mimmen to mask, mom a mask; akin to G. mumme disguise; prob. of
imitative origin, and akin to E. mum, mumble, in allusion to the
indistinctness of speech occasioned by talking from behind a mask.
Cf. Mumble, Mummery.]
Definition: To sport or make diversion in a mask or disguise; to mask.
With mumming and with masking all around. Spenser.
Source: Webster’s Unabridged Dictionary 1913 Edition