Sentence:  Then as they fought on foot, fast and fiercely with their swords, Tristrem, being sorely wounded in the thigh, grew well-nigh mad with pain, and with one <WSD>swift-handed</WSD> heavy stroke cleft Moraunt's helmet to his skull, breaking the sword-point in his brain. 
Meaning of the word marked with <WSD> tags:  Characterized by quick, skillful movements of the hands.