Chiefly British Informal. mother1 (def. 1).
Where did the word Mumsy come from?
Mum's the word is a popular English idiom. It is related to an expression used by William Shakespeare, in Henry VI, Part 2. The word "mum" is an alteration of momme, which was used between 1350 and 1400 in Middle English with very close to the same meaning, "be silent; do not reveal".
What does Mumsy mean in British?
mumsy in British English
(ˈmʌmzɪ ) adjectiveWord forms: -sier or -siest British informal. out of fashion; homely or drab. motherly.