The Nobility
Aristocrat
noun, の adjective
People of a valuable tribe are part of the nobility. Unlike our tribes, they are valuable.
貴族 refers to a noble or aristocrat in old social systems, so you mostly see it in history books or fantasy settings. In modern Japanese, people sometimes use it jokingly when a person does something very luxurious or indulgent — as if they're living like an aristocrat for a moment.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その国では、貴族たちが政治を左右していた。
In that country, the nobles controlled politics.
俺が貴族の血を引いているって言ったら、みんなビックリしてたよ。
Everyone was shocked when I told them I have noble blood.
ああ、もし私が貴族の家柄に生まれていたら、彼女と話をすることも可能だったかもしれないのに。
Ah, if only I had been born into a noble family, I might have been able to talk to her.
自由にいろんなことができる独身者の生活って、まるで貴族みたいでしょ？だから「独身貴族」って言われるんだよ。
A single person who can do whatever they want is basically living like an aristocrat, right? That's why we call them a "single aristocrat."