proportional control

20 LETTERS · STARTS WITH P

proportional control is a valid 20-letter word worth 25 points in Scrabble and 32 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3R1O1P3O1R1T1I1O1N1A1L1C3O1N1T1R1O1L1

3 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 1 =25 PTS

DOUBLE WORD → 50TRIPLE WORD → 75

MEANING

What does proportional control mean?