A limerick is a 5-line poem with a strict AABBA rhyme scheme, often with five-line anapestic meter, sometimes obscene with humorous intent.
A limerick is a form of poetry, typically English, with the purpose of entertaining the reader.
It's made of a stanza of five lines, whose rhyme scheme is AABBA.
Usually, the first line of the limerick defines the protagonist, while the remaining lines describe the anecdote.
Sometimes, the story is nonsense.
A dozen, a gross and a score,
Plus three times the square root of four,
Divided by seven,
Plus five times eleven,
equals nine squared and not a bit more
In the example above the 'A' beats are bolded and the 'B' beats are in italics.