antonomastic
an·to·no·ma·sia
(ăn′tə-nə-mā′zhə)n.
1. The substitution of a title or epithet for a proper name, as in calling a sovereign "Your Majesty."
2. The substitution of a personal name for a common noun to designate a member of a group or class, as in calling a traitor a "Benedict Arnold."
[Latin, from Greek antonomazein, to name instead : anti-, instead of; see anti- + onomazein, to name (from onoma, name; see nō̆-men- in Indo-European roots).]
an′to·no·mas′tic (-măs′tĭk) adj.
an′to·no·mas′ti·cal·ly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.