newlywed vs spouse

newlywed and spouse both are nouns.

Word	Noun	Adjective	Verb	Adverb
newlywed	Yes	No	No	No
spouse	Yes	No	No	No

As nouns, spouse is a hypernym of newlywed; that is, spouse is a word with a broader meaning than newlywed:

Other hypernyms of newlywed include better half, married person, mate, partner.

newlywed (noun)	spouse (noun)
someone recently married	a person's partner in marriage