A limerick is a five-line poem with a strict form (AABBA), originally popularized in English by Edward Lear, which intends to be witty or humorous, and is sometimes obscene with humorous intent. The following example of a limerick is of anonymous origin. Gershon Legman, who compiled the largest and most scholarly anthology, held that the true limerick as a folk form is always obscene, and cites similar opinions by Arnold Bennett and George Bernard Shaw, describing the clean limerick as a periodic fad and object of magazine contests, rarely rising above mediocrity.
From a folkloric point of view, the form is essentially transgressive; violation of taboo is part of its function.