robust vs stalwart

robust is not a noun while stalwart is a noun.

Word	Noun	Adjective	Verb	Adverb
robust	No	Yes	No	No
stalwart	Yes	Yes	No	No

robust (noun)	stalwart (noun)
	a person who is loyal to their allegiance (especially in times of revolt)

robust (adjective)	stalwart (adjective)
sturdy and strong in form, constitution, or construction	used especially of persons
strong enough to withstand or overcome intellectual challenges or adversity	dependable
marked by richness and fullness of flavor	having rugged physical strength; inured to fatigue or hardships
rough and crude