main stem

9 LETTERS · STARTS WITH M

main stem is a valid 9-letter word worth 12 points in Scrabble and 15 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

M3A1I1N1S1T1E1M3

3 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 3 =12 PTS

DOUBLE WORD → 24TRIPLE WORD → 36

MEANING

What does main stem mean?