This is the 5108th most frequent Japanese word.
貴之
"貴之" is a Japanese given name, typically male, meaning "nobility" (貴) and "of" or "possessing" (之).
The word 貴之 is used as a proper noun in this sentence, referring to an individual's name.
貴之さんは音楽が得意です。
Takayuki is skilled at music.
Here, 貴之 is again utilized as a given name referring to a specific person.
昨日、貴之に会ったとき、彼は元気そうだった。
Yesterday, when I met Takayuki, he seemed well.
In this context, 貴之 represents the mention of a person's name generically within the statement.