Explanation: a pun is a humorous use of a word or phrase that has different meanings or that sounds like another word. In the given lines from Act III, Scene 1 from Romeo and Juliet by William Shakespeare, we can see that Mercurio uses a pun when he says "ask for me to-morrow, and you shall find me a grave man" the word "grave" means serious, but in this case he is also referring to the fact that he will be death (and in a grave).
