peeress vs baroness

peeress and baroness both are nouns.

Word	Noun	Adjective	Verb	Adverb
peeress	Yes	No	No	No
baroness	Yes	No	No	No

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

peeress: a woman of the peerage in Britain
baroness: a noblewoman who holds the rank of baron or who is the wife or widow of a baron

Other hyponyms of peeress include countess, duchess, lady-in-waiting, marchioness, marquise, Milady.

peeress (noun)	baroness (noun)
a woman of the peerage in Britain	a noblewoman who holds the rank of baron or who is the wife or widow of a baron