If a plan, a promise, or a person is copper-bottomed, you can depend on it — it is solid, safe, not a gamble. This is especially British English; American speakers are more likely to say rock-solid or watertight.

If a plan, a promise, or a person is copper-bottomed如果一個計畫、承諾或人是copper-bottomed， you can depend on it就表示可以信賴它—— it is solid, safe, not a gamble很穩、很安全，不是賭一把。 This is especially British English這特別是英式英語的說法； American speakers are more likely to say rock-solid or watertight美式說法比較常用rock-solid或watertight。

Though actually it began as a real ship fact, not a metaphor. In the 1700s, wooden ships had copper sheets fixed to the bottom so sea worms and plants would not eat the wood. A copper-bottomed ship lasted.

Though actually不過事實上， it began as a real ship fact這個說法一開始是真實的造船事實， not a metaphor不是比喻。 In the 1700s在十八世紀， wooden ships had copper sheets fixed to the bottom木造船的船底會釘上銅板， so sea worms and plants would not eat the wood好讓海蟲和海藻不會啃蝕木頭。 A copper-bottomed ship lasted底部包銅的船比較耐用。

Britain had a huge navy, so there was always a market for copper in shipbuilding, and copper felt like a safe thing to put money in. From at least 1807 people also used the phrase in a picture way, about trust, not only about boats.

Britain had a huge navy英國有龐大的海軍， so there was always a market for copper in shipbuilding所以造船業對銅一直有需求， and copper felt like a safe thing to put money in銅也讓人覺得是穩當的投資。 From at least 1807至少從1807年起， people also used the phrase in a picture way大家也開始把這個說法用來比喻—— about trust, not only about boats講的是信賴，不只是船了。

In a kitchen, a copper-bottomed pan can still mean a pan with a copper base — but in news and business English it almost always means “reliable.”

In a kitchen在廚房裡， a copper-bottomed pan can still mean a pan with a copper base還是可以單純指底部是銅的鍋子， but in news and business English it almost always means “reliable.”但在新聞和商業英語裡，這個詞幾乎都是指「可靠」。