Meanings
- uncommonMust not (negative auxiliary); used to indicate that something is forbidden or, in a tag question, that something is not necessary.
We must go, mustn't we?
3 more examples
You mustn't blame yourself for this tragedy.
1906, Edith Nesbit, The Railway Children, Chapter 4: The engine-burglar, "Now, listen," said Mother; "it's quite true that we're poor, but we have enough to live on. You mustn't go telling everyone about our affairs--it's not right. And you must never, never, never ask strangers to give you things. Now always remember that--won't you?"
Look, we mustn't mistake ourselves for regular people. We're artists.
1989: Batman (movie)
Origin
Translations
Esperanto ne devas
- ne devassomething is forbidden
Māori me kaua
- me kauasomething is forbidden
Polish nie wolno
- nie wolnosomething is forbidden
Cite this entry
mustn't. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/mustn't
“mustn't.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/mustn't. Accessed November 3, 2026.
WatkinsX Dictionary, s.v. “mustn't,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/mustn't.
Source: mustn't on Wiktionary, CC BY-SA 4.0.