Definition of united kingdoms:
(n) :
A kingdom and country in Northern Europe, comprising the four countries of England, Scotland and Wales on the island of Great Britain, and Northern Ireland on the northeastern portion of the island of Ireland since 1922.
(n) :
(nation's name) A kingdom consisting of several constituencies, either actual, historical, or hypothetical.
(n) :
(historical) The United Kingdom of Great Britain and Ireland (1801–1922).
(n) :
(historical, informal, nonstandard) The Kingdom of Great Britain (1707–1801).