nonconvertibleness

18 LETTERS · 6 SYLLABLES · STARTS WITH N

nonconvertibleness is a valid 18-letter word worth 25 points in Scrabble and 33 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

N1O1N1C3O1N1V4E1R1T1I1B3L1E1N1E1S1S1

1 + 1 + 1 + 3 + 1 + 1 + 4 + 1 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 1 =25 PTS

DOUBLE WORD → 50TRIPLE WORD → 75

MEANING

What does nonconvertibleness mean?