ritual vs marriage

ritual and marriage both are nouns.

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

As nouns, marriage is a hyponym of ritual; that is, marriage is a word with a more specific, narrower meaning than ritual:

Other hyponyms of ritual include betrothal, espousal, marriage ceremony, wedding, rite of passage.

ritual (noun)	marriage (noun)
any customary observance or practice	the act of marrying; the nuptial ceremony
the prescribed procedure for conducting religious ceremonies	two people who are married to each other
stereotyped behavior	the state of being a married couple voluntarily joined for life (or until divorce)
	a close and intimate union

ritual (adjective)	marriage (adjective)
of or relating to or employed in social rites or rituals
of or relating to or characteristic of religious rituals