aristocracy vs peerage

aristocracy and peerage both are nouns.

Word	Noun	Adjective	Verb	Adverb
aristocracy	Yes	No	No	No
peerage	Yes	No	No	No

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

Other hyponyms of aristocracy include noblesse, baronage, baronetage, knighthood, samurai.

aristocracy (noun)	peerage (noun)
a privileged class holding hereditary titles	the peers of a kingdom considered as a group
the most powerful members of a society