continental slope vs bathyal zone

continental slope and bathyal zone both are nouns.

Word	Noun	Adjective	Verb	Adverb
continental slope	Yes	No	No	No
bathyal zone	Yes	No	No	No

As nouns, continental slope and bathyal zone are synonyms defined as:

continental slope and bathyal zone: the steep descent of the seabed from the continental shelf to the abyssal zone

Other synonyms of continental slope include bathyal district.

continental slope (noun)	bathyal zone (noun)
the steep descent of the seabed from the continental shelf to the abyssal zone	the steep descent of the seabed from the continental shelf to the abyssal zone