nonsubstitution

15 LETTERS · 5 SYLLABLES · STARTS WITH N

nonsubstitution is a valid 15-letter word worth 17 points in Scrabble and 23 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

N1O1N1S1U1B3S1T1I1T1U1T1I1O1N1

1 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 =17 PTS

DOUBLE WORD → 34TRIPLE WORD → 51

MEANING

What does nonsubstitution mean?