A five-line humorous poem with an AABBA rhyme scheme is called a limerick. In its standard pattern, the first, second, and fifth lines rhyme, while the shorter third and fourth lines share a second rhyme.
The form appeared in England in the early eighteenth century and developed from an older tradition of comic, sometimes bawdy, drinking songs. A typical limerick uses a lively three-beat rhythm in its longer lines and often begins by introducing a person and a place, with the place name supplying the main rhyme.
The form became especially associated with Edward Lear, whose Book of Nonsense helped popularize its playful sound during the nineteenth century. Lear often wrote limerick-like verses without using the modern term consistently. A common mix-up is to identify any short comic poem as a limerick; the five-line structure and AABBA pattern are the defining clues, even though individual poems may bend the rhythm or rhyme.