1. Britain, the United Kingdom
■ Both of these terms are said to derive from the Portuguese word "Ingles" or "Inglez" and/or the Dutch word "Engelsch," meaning "English". It was originally transliterated as エゲレス and written 英吉利 using 当て字. The pronunciation later changed to イギリス, and the letter 英 of the kanji form was taken to form abbreviation 英国.
□ Considerable confusion exists over what exactly these terms refer to. While the word that gave rise to these terms clearly relates to England and not Britain or the UK, its Japanese derivatives are more ambiguous and have been used to mean both England and the UK as a whole, perhaps because the Japanese in the Edo period were, like many Japanese people today, unaware of the distinction.
The terms イギリス and 英国 both share the same origin and are therefore generally considered synonymous, but some argue that there is, or should be, a distinction between them.
Today it appears that 英国 is the officially recognised abbreviation for the United Kingdom of Great Britain and Northern Ireland (グレート･ブリテン及び北部アイルランド連合王国)。 It is used in the Ministry of Foreign Affairs (外務省) website, and UK NOW, a portal that brings together the websites of the British Embassy, the British Council, the British Tourist Authority and the British Chamber of Commerce in Japan, also uses the term 英国 throughout.
Perhaps because of this official preference for 英国 as a translation of Britain or the UK, some say that イギリス refers to England and 英国 the UK. This distinction is by no means established, however, and both terms are still widely used interchangeably, referring to England as well as the UK.
Where it is necessary to distinguish England from the UK, the more commonly employed method is to refer to the UK as 英国 or イギリス and call England イングランド (the UK NOW website follows this convention). For example, in sports where the four nations of the UK field separate teams in international matches, such as soccer and rugby, the England team is called イングランド代表, not イギリス代表.
There are also instances where both イギリス and 英国 are avoided altogether, with イングランド used for England and 連合王国, ＵＫ or ブリテン used for the UK/Britain, although this approach is seen only where it is felt necessary to avoid the ambiguity of イギリス/英国. Interestingly, the MOFA site calls the British Embassy 連合王国大使館, while the Embassy's own website opts for 英国大使館.