seafloor
/ˈsiːfloʊr/Definitions
1. noun
The bottom of a body of water, especially the ocean, that is not land.
“The ship sank to the seafloor after colliding with an underwater rock.”
2. noun
The lowest layer of the ocean, characterized by a lack of light and limited life forms.
“The deep-sea submersible explored the darkness of the seafloor.”