nonplus

VERB /nɑn'pləs/
7 LETTERS · 2 SYLLABLES · STARTS WITH N

nonplus is a valid 7-letter word worth 9 points in Scrabble and 14 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
N1O1N1P3L1U1S1
1 + 1 + 1 + 3 + 1 + 1 + 1 =9 PTS
DOUBLE WORD → 18TRIPLE WORD → 27
MEANING

What does nonplus mean?