stalwart vs hardy

stalwart is a noun but hardy is not a noun.

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

As adjectives, stalwart and hardy are synonyms defined as:

stalwart and hardy: having rugged physical strength; inured to fatigue or hardships

Other synonyms of stalwart include stout, sturdy.

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

stalwart (adjective)	hardy (adjective)
used especially of persons	invulnerable to fear or intimidation
dependable	having rugged physical strength; inured to fatigue or hardships
having rugged physical strength; inured to fatigue or hardships	able to survive under unfavorable weather conditions