n. Brit. colloq. mother.
Etymology: abbr. of MUMMY(1)
2.
adj. colloq. silent (keep mum).
Phrases and idioms:
mum's the word say nothing.
Etymology: ME: imit. of closed lips
3.
v.intr. (mummed, mumming) act in a traditional masked mime.
Etymology: cf. MUM(2) and MLG mummen
Useful english dictionary. 2012.