U

antonomasia

noun

Rhetoric. the identification of a person by an epithet or appellative that is not the person’s name, as his lordship.
the use of the name of a person who was distinguished by a particular characteristic, as Don Juan or Annie Oakley, to designate a person or group of persons having the same characteristic.

noun rhetoric

the substitution of a title or epithet for a proper name, such as his highness
the use of a proper name for an ideahe is a Daniel come to judgment

use of an epithet for a proper name (or vice versa; e.g. His Holiness for the name of a pope), 1580s, from Latin, from Greek antonomasia, from antonomazein “to name instead, call by a new name,” from anti “instead” (see anti-) + onomazein “to name,” from onoma “name” (see name (n.)).