a person who is engaged to be married (used for either male or female; equivalent to 'fiancé/fiancée').
彼はフィアンセと来年結婚する予定だ。
He plans to marry his fiance next year.
パーティーで彼女のフィアンセに初めて会った。
I met her fiance for the first time at the party.
フィアンセから婚約指輪をもらってとても嬉しかった。
I was very happy to receive an engagement ring from my fiance.