To play the supporting role in a cross-talk performance, reacting to the funny man's lines with words, gestures, or expressions to provoke laughter

to crack jokes or use witty language to provoke laughter, especially in comic performances

vicious and fierce in appearance or manner

(of a performer, typically in traditional arts like cross-talk) to seize on something happening in the moment to make an impromptu joke or funny line

funny; comical; amusing