third part

10 LETTERS · STARTS WITH T

third part is a valid 10-letter word worth 15 points in Scrabble and 15 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

T1H4I1R1D2P3A1R1T1

1 + 4 + 1 + 1 + 2 + 0 + 3 + 1 + 1 + 1 =15 PTS

DOUBLE WORD → 30TRIPLE WORD → 45

MEANING

What does third part mean?