diffraction disk

16 LETTERS · STARTS WITH D

diffraction disk is a valid 16-letter word worth 29 points in Scrabble and 31 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

D2I1F4F4R1A1C3T1I1O1N1D2I1S1K5

2 + 1 + 4 + 4 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 0 + 2 + 1 + 1 + 5 =29 PTS

DOUBLE WORD → 58TRIPLE WORD → 87

MEANING

What does diffraction disk mean?