male aristocrat vs Sir

male aristocrat and Sir both are nouns.

Word	Noun	Adjective	Verb	Adverb
male aristocrat	Yes	No	No	No
Sir	Yes	No	No	No

As nouns, Sir is a hyponym of male aristocrat; that is, Sir is a word with a more specific, narrower meaning than male aristocrat:

Other hyponyms of male aristocrat include cavalier, chevalier, knight, Lord, noble, nobleman.

male aristocrat (noun)	Sir (noun)
a man who is an aristocrat	a title used before the name of knight or baronet