stalwart vs sturdy

stalwart is a noun but sturdy is not a noun.

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

As adjectives, stalwart and sturdy are synonyms defined as:

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

Other synonyms of stalwart include hardy, stout.

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

stalwart (adjective)	sturdy (adjective)
used especially of persons	not making concessions
dependable	having rugged physical strength; inured to fatigue or hardships
having rugged physical strength; inured to fatigue or hardships	substantially made or constructed