A marriage agreement, also known as a prenuptial agreement, is a legally binding contract between two people who are about to be married. The two words that can be used to describe this agreement are 'IDO' and 'YESDEAR'. IDO stands for 'I Do', which is the traditional phrase used in wedding ceremonies when the couple agrees to marry each other. YESDEAR is an informal term of endearment that is often used between couples in a romantic relationship. Both terms are used to signify the commitment and love between two people who are entering into a marriage agreement.