oyster fungus vs oyster agaric

oyster fungus and oyster agaric both are nouns.

Word	Noun	Adjective	Verb	Adverb
oyster fungus	Yes	No	No	No
oyster agaric	Yes	No	No	No

As nouns, oyster fungus and oyster agaric are synonyms defined as:

oyster fungus and oyster agaric: edible agaric with a soft greyish cap growing in shelving masses on dead wood

Other synonyms of oyster fungus include oyster mushroom, Pleurotus ostreatus.

oyster fungus (noun)	oyster agaric (noun)
edible agaric with a soft greyish cap growing in shelving masses on dead wood	edible agaric with a soft greyish cap growing in shelving masses on dead wood