diagnosis vs designation

diagnosis and designation both are nouns.

Word	Noun	Adjective	Verb	Adverb
diagnosis	Yes	No	No	No
designation	Yes	No	No	No

As nouns, designation is a hypernym of diagnosis; that is, designation is a word with a broader meaning than diagnosis:

Other hypernyms of diagnosis include identification.

diagnosis (noun)	designation (noun)
identifying the nature or cause of some phenomenon	the act of putting a person into a non-elective position
	the act of designating or identifying something
	identifying word or words by which someone or something is called and classified or distinguished from others