matrimony vs spousal relationship

matrimony and spousal relationship both are nouns.

Word	Noun	Adjective	Verb	Adverb
matrimony	Yes	No	No	No
spousal relationship	Yes	No	No	No

As nouns, matrimony and spousal relationship are synonyms defined as:

matrimony and spousal relationship: the state of being a married couple voluntarily joined for life (or until divorce)

Other synonyms of matrimony include marriage, union, wedlock.

matrimony (noun)	spousal relationship (noun)
the ceremony or sacrament of marriage	the state of being a married couple voluntarily joined for life (or until divorce)
the state of being a married couple voluntarily joined for life (or until divorce)