Word of the Day:

: the use of a proper name to designate a member of a class (as a Solomon for a wise ruler); also : the use of an epithet or title in place of a proper name (as the Bard for Shakespeare)

"It's antonomasia when you refer to the mayor as His Honor or to Babe Ruth as the Sultan of Swat." (Michael Gartner, Newsday [New York], July 3, 1988)

More example sentences

What's in a name? When it comes to "antonomasia," quite a bit. English speakers picked up that appellative term from Latin, but it traces back to Greek, descending from the verb "antonomazein," meaning "to call by a new name," which itself developed from the Greek noun "onoma," meaning "name." You may already be familiar with some other English "onoma" descendants, such as "onomatopoeia" (the naming of something in imitation of the sound associated with it), "polyonymous" (having multiple names), and "toponymy" (the place-names of a region). "Antonomasia" has been naming names in English since the mid-16th century.