dissociative disorder

NOUN
21 LETTERS · STARTS WITH D

dissociative disorder is a valid 21-letter word worth 28 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
D2I1S1S1O1C3I1A1T1I1V4E1D2I1S1O1R1D2E1R1
2 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 4 + 1 + 0 + 2 + 1 + 1 + 1 + 1 + 2 + 1 + 1 =28 PTS
DOUBLE WORD → 56TRIPLE WORD → 84
MEANING

What does dissociative disorder mean?