Etymology and terminology

The 1707 Acts of Union declared that the Kingdoms of England and Scotland were "United into One Kingdom by the Name of Great Britain" though the new state is also referred to in the Acts as the United Kingdom of Great Britain and the United Kingdom. ^{[23][24][nb 8]} The term United Kingdom is found in informal use during the 18th century and the country was occasionally referred to as the "United Kingdom of Great Britain".^[25] The Acts of Union 1800 united the Kingdom of Great Britain and the Kingdom of Ireland in 1801, and created the United Kingdom of Great Britain and Ireland. The name "United Kingdom of Great Britain and Northern Ireland" was adopted in 1927 by the Royal and Parliamentary Titles Act. It reflected the independence of the Irish Free State, and the partition of Ireland, in 1922, which left Northern Ireland as the only part of the island of Ireland within the UK.^[26]

Although the United Kingdom, as a sovereign state, is a country, England, Scotland, Wales and (more controversially) Northern Ireland are also regarded as 'countries', though not sovereign states. Scotland, Wales and Northern Ireland have devolved self-government.^[27][28] The British Prime Minister's website has used the phrase "countries within a country" to describe the United Kingdom.^[12] With regard to Northern Ireland, the descriptive name used "can be controversial, with the choice often revealing one's political preferences."^[29] Terms used for Northern Ireland include "region" and "province".^[30][31]

The term Britain is often used as synonym for the United Kingdom. The term Great Britain, by contrast, refers geographically to the island of Great Britain, or politically to England, Scotland and Wales in combination.^[32][33][34] However, it is sometimes used as a loose synonym for the United Kingdom as a whole.^[35][36] GB and GBR are the standard country codes for the United Kingdom (see ISO 3166-2 and ISO 3166-1 alpha-3) and are consequently used by international organisations to refer to the United Kingdom. Also, the United Kingdom's Olympic team competes under the name "Great Britain" or "Team GB".^[37][38]

The adjective British is commonly used to refer to matters relating to the United Kingdom. The term has no definite legal connotation, however, it is used in law to refer to UK citizenship and matters to do with nationality.^[39] British people use a number of different terms to describe their national identity and may identify themselves as being British; or as being English, Scottish, Welsh, Northern Irish, or Irish;^[40] or as being both.^[41]

In 2006, a new design of British passport was introduced. Its first page shows the long form name of the state in English, Welsh and Scottish Gaelic.^[42] In Welsh, the long form name of the state is "Teyrnas Unedig Prydain Fawr a Gogledd Iwerddon" with "Teyrnas Unedig" being used as a short form name on government websites.^[43] In Scottish Gaelic, the long form is "Rìoghachd Aonaichte na Breatainne Mòire is Èireann a Tuath" and the short form "Rìoghachd Aonaichte".