civil marriage vs marriage

civil marriage and marriage both are nouns.

Word	Noun	Adjective	Verb	Adverb
civil marriage	Yes	No	No	No
marriage	Yes	No	No	No

As nouns, marriage is a hypernym of civil marriage; that is, marriage is a word with a broader meaning than civil marriage:

civil marriage: a marriage performed by a government official rather than by a clergyman
marriage: the act of marrying; the nuptial ceremony

Other hypernyms of civil marriage include marriage ceremony, wedding.

civil marriage (noun)	marriage (noun)
a marriage performed by a government official rather than by a clergyman	the act of marrying; the nuptial ceremony
	two people who are married to each other
	the state of being a married couple voluntarily joined for life (or until divorce)
	a close and intimate union