noun
marriage partner; spouse
Refers to the person one is married to, regardless of gender.
結婚相手とは価値観が合うことが大切だ。
It's important to share values with your marriage partner.
noun
future spouse
Used for someone one is engaged or planning to marry; context determines gender.
彼は結婚相手を両親に紹介した。
He introduced his future spouse to his parents.