Till/Until the cows come home 意為「長時間地；很久」(for a very long time)。這個慣用語從 1500 年代末期開始使用至今，可能源自蘇格蘭高地；當地的母牛群每年都會被放牧好幾個月，優哉游哉地在牧場上吃草，到了入秋之際才慢條斯理地閒逛返回牠們的農場。
例句：
- They could sit here and argue till the cows come home, but it wouldn’t solve anything. (他們可以坐在這裡無休止地爭論下去，但那樣解決不了任何問題)
- My husband was talking on the phone with his brother till the cows came home last night. (我先生昨晚跟他弟弟講了好久好久的電話)
- You can talk till the cows come home, but you’ll never persuade me to lend you the money! (你可以不停地一直說下去，但你絕不可能說服我借你錢！)
- You can wait until the cows come home, but you’ll never see these measures taken in this company! (你可以等到天荒地老，但你絕不會看到這家公司採取這些措施！)