bathyal district vs Davy Jones

bathyal district and Davy Jones both are nouns.

Word	Noun	Adjective	Verb	Adverb
bathyal district	Yes	No	No	No
Davy Jones	Yes	No	No	No

As nouns, Davy Jones is a hypernym of bathyal district; that is, Davy Jones is a word with a broader meaning than bathyal district:

bathyal district: the steep descent of the seabed from the continental shelf to the abyssal zone
Davy Jones: the bottom of a sea or ocean

Other hypernyms of bathyal district include Davy Jones's locker, ocean bottom, ocean floor, sea bottom, sea floor, seabed.

bathyal district (noun)	Davy Jones (noun)
the steep descent of the seabed from the continental shelf to the abyssal zone	the bottom of a sea or ocean