prenuptial agreement
noun [ C ] uk/ˌpriːˈnʌp.ʃəl əˈɡriː.mənt/ us/ˌpriːˈnʌp.ʃəl əˈɡriː.mənt/ (informal prenup, uk/ˈpriːnʌp/ us)
婚前协议
an official document signed by two people before they get married that says what will happen to their possessions and/or children if they divorce (= officially stop being married)
He asked her to sign a prenuptial agreement when they got engaged. 他们订婚时他要求她签了一份婚前协议。