the date after which an official document, agreement, etc. is no longer valid （文件、协议等）到期日，截止日◆What is the expiry date on your credit card? 你的信用卡甚麽时候到期？
() the final or only day on which you can use your right to buy or sell particular shares, bonds, etc. (an option) 到期日（行使期权买卖特定股票、债券等的最後一天或唯一的一天）
the date, printed on a container or package, by which an item of food, a medicine, etc. should be eaten or a product should be used. The items must not be sold after this date （食品、药品等包装上注明的）保质期，有效期◆Do not take medicine after its expiry date. 不要吃过期的药品。➡ see note at best-before date