This is the 5972nd most frequent Japanese word.
アイツ
"Aitsu" (アイツ) is a casual or informal term meaning "that guy," "that person," or "he/she." It can sound rude or impolite depending on context.
In this sentence, 'アイツ' is used to informally refer to a person, often implying familiarity or possibly a casual tone.
アイツは昨日遅刻した。
That guy was late yesterday.
Here, 'アイツ' is applied to show admiration or praise towards someone, utilizing it in a colloquial manner.
アイツの絵はすごく上手だよ。
That person's drawings are really amazing.
In this case, 'アイツ' is employed to express a slightly critical or teasing tone towards the mentioned person.