nobility vs aristocracy

nobility and aristocracy both are nouns.

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

As nouns, nobility and aristocracy are synonyms defined as:

nobility (noun)	aristocracy (noun)
the quality of elevation of mind and exaltation of character or ideals or conduct	a privileged class holding hereditary titles
a privileged class holding hereditary titles	the most powerful members of a society
the state of being of noble birth