overkingdom means A unit composed of several kingdoms and presided over by an overking; an empire. Lexicurio rates it Rare gem — a strength score of 83 out of 100.
Etymology
From over- + kingdom.
noun
- A unit composed of several kingdoms and presided over by an overking; an empire.“The overkingdom of Airgialla comprising Armagh, Monaghan, parts of Louth, Fermanagh, and Tyrone, had ceased to be when the Book of Rights was compiled.”