lazaretto vs infirmary

lazaretto and infirmary both are nouns.

Word	Noun	Adjective	Verb	Adverb
lazaretto	Yes	No	No	No
infirmary	Yes	No	No	No

As nouns, infirmary is a hypernym of lazaretto; that is, infirmary is a word with a broader meaning than lazaretto:

lazaretto: hospital for persons with infectious diseases (especially leprosy)
infirmary: a health facility where patients receive treatment

Other hypernyms of lazaretto include hospital.

lazaretto (noun)	infirmary (noun)
hospital for persons with infectious diseases (especially leprosy)	a health facility where patients receive treatment
a small locker at the stern of a boat or between decks of a ship