the length of time that a product, especially food, can be kept in a shop before it becomes too old to be sold or used

Fresh fruit has a very short shelf life. 新鲜水果的保质期很短。

the length of time that something remains useful, popular, or successful

These days many marriages have a fairly short shelf life (= don't last very long). 这个时代，许多婚姻都无法持久。