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Law of the Medes and the Persians

American  

noun

  1. unalterable law.

Etymology

Origin of Law of the Medes and the Persians

Middle English word dating back to 1350–1400

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.