Sentence:  He bowed slightly to K.'s uncle, who appeared very flattered to make this new acquaintance, yet, being by nature incapable of expressing obligation, <WSD>requited</WSD> the Clerk of the Court's words with a burst of embarrassed but raucous laughter. 
Meaning of the word marked with <WSD> tags:  To return something (usually something figurative) that has been given; to repay; to recompense