ocean floor

NOUN
11 LETTERS · STARTS WITH O

ocean floor is a valid 11-letter word worth 15 points in Scrabble and 18 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
O1C3E1A1N1F4L1O1O1R1
1 + 3 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 1 + 1 =15 PTS
DOUBLE WORD → 30TRIPLE WORD → 45
MEANING

What does ocean floor mean?