piston motion

13 LETTERS · STARTS WITH P

piston motion is a valid 13-letter word worth 16 points in Scrabble and 20 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3I1S1T1O1N1M3O1T1I1O1N1

3 + 1 + 1 + 1 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 =16 PTS

DOUBLE WORD → 32TRIPLE WORD → 48

MEANING

What does piston motion mean?