benthos vs benthonic zone

benthos and benthonic zone both are nouns.

Word	Noun	Adjective	Verb	Adverb
benthos	Yes	No	No	No
benthonic zone	Yes	No	No	No

As nouns, benthos and benthonic zone are synonyms defined as:

benthos and benthonic zone: a region including the bottom of the sea and the littoral zones

Other synonyms of benthos include benthic division.

benthos (noun)	benthonic zone (noun)
organisms (plants and animals) that live at or near the bottom of a sea, lake, river or stream	a region including the bottom of the sea and the littoral zones
a region including the bottom of the sea and the littoral zones