The Bedford Glossary of Critical and Literary Terms - Ross Murfin 2018
Epideictic: From the Greek for “display,” a term referring to poems (epideictic poetry), speeches (epideictic rhetoric), and essays (epideictic prose) meant to edify an audience by demonstrating the strengths (or, on rare occasions, the weaknesses) of some person or persons through praise (or blame). Works of epideictic prose are sometimes referred to as prose encomiums.
EXAMPLES: Statius’s Silvae (c. A.D. 75) is a classical example of epideictic poetry; a more recent instance is Robert Hayden’s poem “Frederick Douglass” (1962). Abraham Lincoln’s “Gettysburg Address” (1863) is perhaps the best-known piece of epideictic rhetoric, whereas Samuel Johnson’s Preface to Shakespeare (1765), a prose encomium, exemplifies epidiectic prose.