retention vs anamnesis

retention and anamnesis both are nouns.

Word	Noun	Adjective	Verb	Adverb
retention	Yes	No	No	No
anamnesis	Yes	No	No	No

As nouns, anamnesis is a hyponym of retention; that is, anamnesis is a word with a more specific, narrower meaning than retention:

Other hyponyms of retention include recollection, remembrance.

retention (noun)	anamnesis (noun)
the act of retaining something	the ability to recall past occurrences
the power of retaining liquid	the case history of a medical patient as recalled by the patient
the power of retaining and recalling past experience