Making a guest appearance; appearing temporarily on a TV show, stage, or program as a guest (not a regular cast member).
来週のドラマにゲスト出演することになりました。
I've been asked to make a guest appearance on next week's drama.
有名俳優がゲスト出演したため、視聴率が上がった。
Ratings went up because a famous actor guest-starred.
彼はバラエティ番組でゲスト出演として昔の話をした。
He appeared as a guest on a variety show and talked about his past.