illiterate person

NOUN
17 LETTERS · STARTS WITH I

illiterate person is a valid 17-letter word worth 18 points in Scrabble and 22 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
I1L1L1I1T1E1R1A1T1E1P3E1R1S1O1N1
1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 =18 PTS
DOUBLE WORD → 36TRIPLE WORD → 54
MEANING

What does illiterate person mean?