blabbermouth

NOUN /blæbər,maʊθ/
12 LETTERS · 3 SYLLABLES · STARTS WITH B

blabbermouth is a valid 12-letter word worth 23 points in Scrabble and 28 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
B3L1A1B3B3E1R1M3O1U1T1H4
3 + 1 + 1 + 3 + 3 + 1 + 1 + 3 + 1 + 1 + 1 + 4 =23 PTS
DOUBLE WORD → 46TRIPLE WORD → 69
MEANING

What does blabbermouth mean?