[intransitive] (about a contract, an offer, an agreement, etc.) to be no longer valid because the period of time that it lasts has come to an end or because payments have not been made
（指合同、报价、协议等）失效，期满终止◆The patent on the drug lapses in 2012.
药品的专利於 2012 年期满终止。◆We must decide whether to renew the lease or allow it to lapse.
我们必须决定延长租约还是让租约失效。◆A life insurance policy lapses when you stop paying the premiums.
当你停止缴纳保费，寿险保单即失效。 ▸ lapsed

adjective

●ˈlapse into sthto gradually pass into a worse or less active state
（逐渐）陷入，进入◆The economy has lapsed into a mild recession.
经济已渐渐陷入轻微的衰退。