dimorphism vs polymorphism

dimorphism and polymorphism both are nouns.

Word	Noun	Adjective	Verb	Adverb
dimorphism	Yes	No	No	No
polymorphism	Yes	No	No	No

As nouns, polymorphism is a hypernym of dimorphism; that is, polymorphism is a word with a broader meaning than dimorphism:

dimorphism: (biology) the existence of two forms of individual within the same animal species (independent of sex differences)
polymorphism: (biology) the existence of two or more forms of individuals within the same animal species (independent of sex differences)

As nouns, polymorphism is a hypernym of dimorphism; that is, polymorphism is a word with a broader meaning than dimorphism:

dimorphism: (chemistry) the property of certain substances that enables them to exist in two distinct crystalline forms
polymorphism: (chemistry) the existence of different kinds of crystal of the same chemical compound

Other hypernyms of dimorphism include pleomorphism.

dimorphism (noun)	polymorphism (noun)
(biology) the existence of two forms of individual within the same animal species (independent of sex differences)	(biology) the existence of two or more forms of individuals within the same animal species (independent of sex differences)
(chemistry) the property of certain substances that enables them to exist in two distinct crystalline forms	(chemistry) the existence of different kinds of crystal of the same chemical compound
	(genetics) the genetic variation within a population that natural selection can operate on