1. Control or the exercise of control; sovereignty: "The devil . . . has their souls in his possession, and under his dominion" (Jonathan Edwards).
2. A territory or sphere of influence or control; a realm.
3. often Dominion (Abbr. Dom.) One of the self-governing nations within the British Commonwealth.
4. dominions Christianity. See domination (sense 2).

[Middle English dominioun, from Old French dominion, from Medieval Latin dominiō, dominiōn-, from Latin dominium, property, from dominus, lord.]

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.