levelling screw

15 LETTERS · STARTS WITH L

levelling screw is a valid 15-letter word worth 23 points in Scrabble and 30 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

L1E1V4E1L1L1I1N1G2S1C3R1E1W4

1 + 1 + 4 + 1 + 1 + 1 + 1 + 1 + 2 + 0 + 1 + 3 + 1 + 1 + 4 =23 PTS

DOUBLE WORD → 46TRIPLE WORD → 69

MEANING

What does levelling screw mean?