You searched for: “antonomasias
antonomasia (s) (noun), antonomasias (pl)
1. The use of a title or formal description such as "Your Highness" or "His Excellency" in place of someone's proper name.
2. The expression of a proper name as a common noun to refer to someone or something with associated characteristics, e.g., in calling a handsome young man "an adonis".