The Columbia Encyclopedia, Sixth Edition. 2001-07.
limerick, in poetry
type of humorous verse. It is always short, often nonsensical, and sometimes ribald. Of unknown origin, the limerick is popular rather than literary and has even been used in advertising. The rhyme scheme of most limericks is usually aabba, as in the following example:
There was an old man from Peru, Who dreamed he was eating his shoe. He woke in a fright In the middle of the night And found it was perfectly true.
The most famous collection of limericks is Edward Lears Book of Nonsense (1846).
See L. Reed, The Complete Limerick Book (1925); C. P. Aiken, A Seizure of Limericks (1964); V. B. Holland, An Explosion of Limericks (1967); W. S. Baring-Gould, The Lure of the Limerick (1967).