mother-in-law vs Naomi

mother-in-law and Naomi both are nouns.

Word	Noun	Adjective	Verb	Adverb
mother-in-law	Yes	No	No	No
Naomi	Yes	No	No	No

mother-in-law (noun)	Naomi (noun)
the mother of your spouse	the mother-in-law of Ruth whose story is told in the Book of Ruth in the Old Testament