How does Mercutio’s “grave man” line in Romeo and Juliet use a pun?

In William Shakespeare’s Romeo and Juliet, Mercutio employs a pun when he says, "Ask for me tomorrow, and you shall find me a grave man." This line is a classic example of a play on words that utilizes two distinct meanings of the adjective "grave" simultaneously.1

First, the word refers to a serious or solemn demeanor, reflecting Mercutio’s state as he lies dying. Second, it functions as a noun-derived adjective referring to a burial site or tomb. By using this rhetorical device, Shakespeare highlights the tragic irony of the moment: Mercutio, known for his wit and humor, uses his final breath to make a dark, cynical joke about his own impending death. The pun effectively bridges his character's playful nature with the grim reality of his fatal injury.21