Irony is a figure of speech that uses words to convey a meaning that is different from the literal meaning of the words. It is often used to create humor or to make a point about something. In a poem, irony can be used to create a sense of tension or to subvert the reader's expectations.
For example, a poem that includes statements that appear self-contradictory can create a sense of irony. This is because the reader is expecting the poem to make sense, but instead it does not. This can create a sense of confusion or amusement, and it can make the reader think more deeply about the poem's meaning.