Shakespeare plays on the word "nothing" and the idea of nothingness or emptiness throughout King Lear.
Here are a few significant moments from the play: In Act 1, when Lear stages his love test and asks Cordelia "What can you say to draw a third [of the kingdom] more opulent than your sisters?", Cordelia replies, "Nothing." Lear can't believe what he's hearing. "Nothing will come of nothing," he tells her. "Speak again." (In other words, you'll get absolutely nothing from me unless you speak up about how much you love me.) By the way, the phrase "Nothing can come of nothing" is a variation on the famous phrase "ex nihilo nihil fit" – that's Latin for "from nothing, nothing comes," which is an ancient Greek philosophical and scientific expression. It's the opposite of the biblical notion that God created the world (which is a whole lot of something) out of nothing (Genesis 1:1).
The word "nothing" shows up again in the play when the Fool tells Lear he is nothing without his crown and power: "now thou art an O without a figure. I am better than thou art now; I'm a fool, thou art nothing" (1.4.17). According to the Fool, King Lear is a zero and is no better than a "shealed peascod" (an empty peapod). The Fool also calls the retired king "Lear's shadow," which suggests that Lear, without his crown, is merely a shadow of his former self. The idea is that Lear, (whose status has changed since retirement) is nothing without his former power and title. Check out our discussion of the theme of "Power" for more on this.