mustn't

7 LETTERS · STARTS WITH M

mustn't is a valid 7-letter word worth 8 points in Scrabble and 11 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3U1S1T1N1'0T1
3 + 1 + 1 + 1 + 1 + 0 + 1 =8 PTS
DOUBLE WORD → 16TRIPLE WORD → 24
MEANING

What does mustn't mean?

1