old hat
陳舊，過時，不再新鮮或有趣的事物
口語·形容過時或老套
英文釋義
outdated or no longer interesting; something that is considered to be too familiar, common, or overused
例句
Wearing bell-bottoms is old hat now; nobody does it anymore.
典故來源
20世紀初，舊帽子象征過時，比喻事物不再流行或新鮮。