The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Exemplum: A story, often an anecdote, told to illustrate a moral point or lesson; a type of allegory. Medieval preachers made frequent use of this device — so much so, in fact, that they occasionally lost sight of their moral point while recounting their exempla, or “examples.” This tendency was criticized by contemporaries such as Florentine epic poet Dante Alighieri. Although exempla seem rather ridiculous to modern readers, they held wide appeal for medieval audiences, who appreciated their concreteness and applicability to daily life.
EXAMPLES: Exempla can be found throughout Geoffrey Chaucer’s Canterbury Tales (c. 1387). The “Nun’s Priest’s Tale,” a beast fable, contains several exempla, and “The Pardoner’s Tale” is itself an exemplum.