dinner gown

NOUN
11 LETTERS · STARTS WITH D

dinner gown is a valid 11-letter word worth 15 points in Scrabble and 19 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
D2I1N1N1E1R1G2O1W4N1
2 + 1 + 1 + 1 + 1 + 1 + 0 + 2 + 1 + 4 + 1 =15 PTS
DOUBLE WORD → 30TRIPLE WORD → 45
MEANING

What does dinner gown mean?