statute of limitations; lapse of rights after a period of time; prescription (including acquisitive and extinctive prescription)
becoming invalid or void after a set time
《chemistry》ageing; aging
殺人罪の時効は二十五年である。
The statute of limitations for murder is twenty-five years.
事件から十五年が経ち時効が成立した。
Fifteen years passed since the incident and the statute of limitations expired.
重大犯罪の時効撤廃を求める声が高まった。
Calls grew louder for abolishing the statute of limitations for serious crimes.