Latter-Day Saint vs Protestant

Latter-Day Saint and Protestant both are nouns.

Word	Noun	Adjective	Verb	Adverb
Latter-Day Saint	Yes	No	No	No
Protestant	Yes	Yes	No	No

As nouns, Protestant is a hypernym of Latter-Day Saint; that is, Protestant is a word with a broader meaning than Latter-Day Saint:

Latter-Day Saint: a member of the Church of Jesus Christ of Latter-Day Saints
Protestant: an adherent of Protestantism

Latter-Day Saint (noun)	Protestant (noun)
a member of the Church of Jesus Christ of Latter-Day Saints	the Protestant churches and denominations collectively
	an adherent of Protestantism

Latter-Day Saint (adjective)	Protestant (adjective)
	of or relating to Protestants or Protestantism