tongue and groove joint

NOUN
23 LETTERS · STARTS WITH T

tongue and groove joint is a valid 23-letter word worth 33 points in Scrabble and 42 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
T1O1N1G2U1E1A1N1D2G2R1O1O1V4E1J8O1I1N1T1
1 + 1 + 1 + 2 + 1 + 1 + 0 + 1 + 1 + 2 + 0 + 2 + 1 + 1 + 1 + 4 + 1 + 0 + 8 + 1 + 1 + 1 + 1 =33 PTS
DOUBLE WORD → 66TRIPLE WORD → 99
MEANING

What does tongue and groove joint mean?

NOUN · 1 SENSE
1

A mortise joint made by fitting a projection on the edge of one board into a matching groove on another board.