Meaning

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

adjective having rugged physical strength; inured to fatigue or hardships

adjective dependable

originBorrowed from Scots stalwart under the influence of Walter Scott, displacing earlier stalworth, wherewith it forms a doublet. From Middle English stal-worth (“physically strong, hardy, robust; brave, courageous”), from Old English stǣlwierþe (“able to stand in good stead, serviceable”), probably from staþol (“establishment; foundation”) (ultimately from Proto-Indo-European *steh₂- (“to stand…

Etymology from Wiktionary, CC BY-SA 3.0