promise to wed; period of preparation before marriage
An engagement is an agreement or promise to marry, and also refers to the time between proposal and marriage. During this time, a couple is said to be affianced, engaged to be married, or simply engaged. An engagement can be seen by witnesses to confirm their marriage.
A fiance is the man who is engaged. A fiancee is the woman who is engaged.
Traditionally, a ring is presented during the engagement ceremony.