Self
Oneself
noun, の adjective
Your self oneself, is your oneself or self.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
彼は、「俺様が一番好きな歌手は俺様自身だよ」と自己満足の笑みを浮かべながら豪語していた。
He was very proud of himself and said, "I’m my own favorite singer," with a very self-satisfied smile.