limerick (n.) Look up limerick at Dictionary.com
nonsense verse of five lines, 1896, perhaps from the county and city in Ireland, but if so the connection is obscure. Often (after OED's Murray) attributed to a party game in which each guest in turn made up a nonsense verse and all sang a refrain with the line "Will you come up to Limerick?" but he reported this in 1898 and earlier evidence is wanting. Or perhaps from Learic, from Edward Lear (1812-1888) English humorist who popularized the form. Earliest examples are in French, which further complicates the quest for the origin. OED's first record of the word is in a letter of Aubrey Beardsley. The place name is literally "bare ground," from Irish Liumneach, from lom "bare, thin." It was famous for hooks.
The limerick may be the only traditional form in English not borrowed from the poetry of another language. Although the oldest known examples are in French, the name is from Limerick, Ireland. John Ciardi suggests that the Irish Brigade, which served in France for most of the eighteenth centiry, might have taken the form to France or developed an English version of a French form. ... The contemporary limerick usually depends on a pun or some other turn of wit. It is also likely to be somewhat suggestive or downright dirty." [Miller Williams, "Patterns of Poetry," Baton Rouge: Louisiana State University, 1986]