x-raying

NOUN
8 LETTERS · STARTS WITH X

x-raying is a valid 8-letter word worth 18 points in Scrabble and 19 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
X8-0R1A1Y4I1N1G2
8 + 0 + 1 + 1 + 4 + 1 + 1 + 2 =18 PTS
DOUBLE WORD → 36TRIPLE WORD → 54
MEANING

What does x-raying mean?