ty·rant

(tī′rənt

n. 1. An extremely oppressive, unjust, or cruel ruler. 2. An absolute ruler who governs without restrictions, especially one who seized power illegally. 3. An oppressive, harsh, arbitrary person: My boss is a tyrant.

[Middle English, from Old French, alteration (influenced by -ant , present participle ending) of tyran , from Latin tyrannus , from Greek turannos , absolute ruler, despot, possibly from Luwian tarwanis , ruler; see terə- 2 in the Appendix of Indo-European roots.]

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.