collision diameter

18 LETTERS · STARTS WITH C

collision diameter is a valid 18-letter word worth 22 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

C3O1L1L1I1S1I1O1N1D2I1A1M3E1T1E1R1

3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 2 + 1 + 1 + 3 + 1 + 1 + 1 + 1 =22 PTS

DOUBLE WORD → 44TRIPLE WORD → 66

MEANING

What does collision diameter mean?