Uk, United Kingdom, England
The England country is where England is. This word can refer to Britain, the United Kingdom and England!
Note that イギリス is more common for "England" - but, since this is a kanji learning website you should learn this word.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
It was very tough work persuading the stubborn British prime minister, wasn't it?
A great number of people visit United Kingdom to golf every year.
The UK has an antagonistic relationship with the US.