Sentence:  The humor of my proposition appealed more strongly to Miss Trevor than I had looked for, and from that time forward she became her old self again;nb.... Our table in the dining-room became again the abode of scintillating wit and caustic <WSD>repartee</WSD>, Farrar bracing up to his old standard, and the demand for seats in the vicinity rose to an animated competition. 
Meaning of the word marked with <WSD> tags:  Skill in replying swiftly and wittily.