neritic zone vs seabed

neritic zone and seabed both are nouns.

Word	Noun	Adjective	Verb	Adverb
neritic zone	Yes	No	No	No
seabed	Yes	No	No	No

As nouns, seabed is a hypernym of neritic zone; that is, seabed is a word with a broader meaning than neritic zone:

neritic zone: the ocean waters from the low tide mark to a depth of about 100 fathoms
seabed: the bottom of a sea or ocean

Other hypernyms of neritic zone include Davy Jones's locker, Davy Jones, ocean bottom, ocean floor, sea bottom, sea floor.

neritic zone (noun)	seabed (noun)
the ocean waters from the low tide mark to a depth of about 100 fathoms	the bottom of a sea or ocean