isomorphy vs isomorphism

isomorphy and isomorphism both are nouns.

Word	Noun	Adjective	Verb	Adverb
isomorphy	Yes	No	No	No
isomorphism	Yes	No	No	No

As nouns, isomorphy and isomorphism are synonyms defined as:

isomorphy and isomorphism: (biology) similarity or identity of form or shape or structure

isomorphy (noun)	isomorphism (noun)
(biology) similarity or identity of form or shape or structure	(biology) similarity or identity of form or shape or structure