double possessive

17 LETTERS · STARTS WITH D

double possessive is a valid 17-letter word worth 24 points in Scrabble and 29 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

D2O1U1B3L1E1P3O1S1S1E1S1S1I1V4E1

2 + 1 + 1 + 3 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 4 + 1 =24 PTS

DOUBLE WORD → 48TRIPLE WORD → 72

MEANING

What does double possessive mean?