unlawful carnal knowledge

NOUN
25 LETTERS · STARTS WITH U

unlawful carnal knowledge is a valid 25-letter word worth 40 points in Scrabble and 51 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
U1N1L1A1W4F4U1L1C3A1R1N1A1L1K5N1O1W4L1E1D2G2E1
1 + 1 + 1 + 1 + 4 + 4 + 1 + 1 + 0 + 3 + 1 + 1 + 1 + 1 + 1 + 0 + 5 + 1 + 1 + 4 + 1 + 1 + 2 + 2 + 1 =40 PTS
DOUBLE WORD → 80TRIPLE WORD → 120
MEANING

What does unlawful carnal knowledge mean?