Sentence:  The "Sarazin" ſore daunted with the buffe / Snatcheth his ſword, and fiercely to him flies; / Who well it wards, and quyteth cuff with cuff: / Each others equall puiſſaunce enuies, / And through their iron ſides with cruelties / Does ſeeke to perce: <WSD>repining</WSD> courage yields / No foote to foe. 
Meaning of the word marked with <WSD> tags:  To fail; to wane.