bathylithic
/bæθɪˈlaɪθɪk/Definitions
1. adjective
relating to or characteristic of great depths, especially of the sea.
“The bathylithic creatures that inhabit the deepest parts of the ocean remain largely unknown to science.”
2. noun
a deep-sea rock or formation.
“The research team discovered a unique bathylithic structure in the abyssal plain.”