not square

10 LETTERS · STARTS WITH N

not square is a valid 10-letter word worth 18 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

N1O1T1S1Q10U1A1R1E1

1 + 1 + 1 + 0 + 1 + 10 + 1 + 1 + 1 + 1 =18 PTS

DOUBLE WORD → 36TRIPLE WORD → 54

MEANING

What does not square mean?