unfashionable vs stick-in-the-mud

unfashionable is not a noun while stick-in-the-mud is a noun.

Word	Noun	Adjective	Verb	Adverb
unfashionable	No	Yes	No	No
stick-in-the-mud	Yes	Yes	No	No

unfashionable (noun)	stick-in-the-mud (noun)
	someone who moves slowly

unfashionable (adjective)	stick-in-the-mud (adjective)
not in accord with or not following current fashion	(used pejoratively) out of fashion; old fashioned
unpopular and considered unappealing or unfashionable at the time