The United Kingdom of Great Britain and Northern Ireland[note 5] (commonly known as the United Kingdom, the UK or Britain) is a sovereign state located off the north-western coast of continental Europe.
That's what Wikipedia tells about it.
And, according to your definition, a soccer team makes a nation? Well I bet there are plenty of nations in eastern Europe, south-east Asia, Oceania, and around the Caribbean Sea that don't have national soccer teams! And I think Scotland only has it own soccer team because they were the first national soccer team in the world, and in that time, Scotland was independent.
Wikipedia:
Scotland maintains its own national side that competes in all major professional tournaments with the exception of the Olympic Games, as Scotland is not a member of the International Olympic Committee.
So, a lot of sports, but not on the Olympic games? The biggest international sports event in the world? Don't call nations nations because it says so on the title.
Count how many countries call themselves something they are not! Examples are spread around space and time, varying from the People's Republic of China, where people can't say anything, to the DDR, the Deutsche Demokratische Republik! That was East Germany, everything but democratic if you ask me.
So my definition of a country is a place in the world with population, land area, a government, has been recognized by more than 50% of the UN, and is a member of the UN itself. And Scotland fails at the last two points.