This is the 11363rd most frequent Korean word.
김지석이
"김지석이" is likely a Korean name and does not have a specific meaning beyond being a proper noun.
The word '김지석이' is used here as the subject of the sentence and takes the topic marker '은/는' to indicate the focus of the sentence.
김지석이는 학교에 갑니다.
Kim Ji-seok is going to school.
In this sentence, '김지석이' is the object of the verb '좋아하다', with the object marker '를/을' attached to denote its role.
나는 김지석이를 좋아합니다.
I like Kim Ji-seok.
Here, '김지석이' is used as the possessor of the item and takes the possessive marker '의' to signify ownership.