Do you know ghouls from goblins and ghosts?
1570s, "descriptive name for a person or thing," from Middle French épithète or directly from Latin epitheton, from Greek epitheton "something added," adjective often used as noun, from neuter of epithetos "attributed, added," from epitithenai "to add on," from epi "in addition" (see epi-) + tithenai "to put" (see factitious).
an adjective or phrase that is used to express the characteristic of a person or thing, such as Ivan the Terrible. In literature, the term is considered an element of poetic diction, or something that distinguishes the language of poetry from ordinary language. Homer used certain epithets so regularly that they became a standard part of the name of the thing or person described, as in "rosy-fingered Dawn" and "gray-eyed Athena." The device was used by many later poets, including John Keats in his sonnet "On First Looking into Chapman's Homer": Oft of one wide expanse had I been toldThat deep-browed Homer ruled as his demesne.