1.Definition: dependable

"The stalwart citizens at Lexington", "A stalwart supporter of the UN"

Related Adjective(s):stout

2.Definition: having rugged physical strength; inured to fatigue or hardships

"Proud of her tall stalwart son"

Related Adjective(s):hardy, stout, sturdy

3.Definition: used especially of persons

"A stalwart knight"

Related Adjective(s):stouthearted