proper function

15 LETTERS · STARTS WITH P

proper function is a valid 15-letter word worth 23 points in Scrabble and 29 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3R1O1P3E1R1F4U1N1C3T1I1O1N1

3 + 1 + 1 + 3 + 1 + 1 + 0 + 4 + 1 + 1 + 3 + 1 + 1 + 1 + 1 =23 PTS

DOUBLE WORD → 46TRIPLE WORD → 69

MEANING

What does proper function mean?