corroborative

ADJECTIVE
13 LETTERS · 5 SYLLABLES · STARTS WITH C

corroborative is a valid 13-letter word worth 20 points in Scrabble and 23 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3O1R1R1O1B3O1R1A1T1I1V4E1
3 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 4 + 1 =20 PTS
DOUBLE WORD → 40TRIPLE WORD → 60
MEANING

What does corroborative mean?