はいぐうしゃ配偶者haiguusha
1.

A term used to refer to one half of a married couple, emphasizing the relationship between the two individuals as partners in matrimony.

2.

A legal designation in which one person in a marriage is identified in relation to their counterpart, highlighting the mutual recognition in the context of marriage.

3.

A word that conveys the notion of companionship and partnership within the framework of a marital relationship, applicable to both husbands and wives.

Example:

彼女は彼が貧しいときも彼を支えるすばらしい配偶者だった。