1. Government by a monarch.
2. A state ruled or headed by a monarch.

[Middle English monarchie, from Old French, from Latin monarchia, from Greek monarkhiā, from monarkhos, monarch. See monarch.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.