Placing opposing ideas or words side by side, so that one lights up the other through contrast.
In Macbeth
Tomorrow, and tomorrow, and tomorrow, / Creeps in this petty pace from day to day, / To the last syllable of recorded time; [...] Life's but a walking shadow, a poor player / That struts and frets his hour upon the stage / And then is heard no more. It is a tale / Told by an idiot, full of sound and fury, / Signifying nothing.
Life is "full of sound and fury and empty of meaning": the two opposing terms show noise without content. The contrast between too much noise and no sense sums up Macbeth’s verdict on his own existence.