affiance

An engagement or betrothal is the relationship between two people who want to get married, and also the period of time between a marriage proposal and a marriage. During this period, a couple is said to be betrothed, intended, affianced, engaged to be married, or simply engaged. Future brides and grooms may be called the betrothed, a wife-to-be or husband-to-be, fiancée or fiancé (from the French), respectively. The duration of the courtship varies vastly, and is largely dependent on cultural norms or upon the agreement of the parties involved. https://en.wikipedia.org/wiki/Engagement