Sentence:  Debonair youth! The spurs, the wide felt hat, the open shirt, the belt holding the array of small pouches, including a holstered revolver, the delight in the long stock-whip having a bright green silk cracker to produce loud reports, ranging from slow rifle fire to the rat-tat-tat of a machine-gun, all told the story of <WSD>zestful</WSD> youth. 
Meaning of the word marked with <WSD> tags:  Having a spirited love of life; ebullient.