prong key

9 LETTERS · STARTS WITH P

prong key is a valid 9-letter word worth 18 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3R1O1N1G2K5E1Y4

3 + 1 + 1 + 1 + 2 + 0 + 5 + 1 + 4 =18 PTS

DOUBLE WORD → 36TRIPLE WORD → 54

MEANING

What does prong key mean?