The Irish are a nation, a people with a unique language and identity. That is what OP is referring to. It the same definition of nation as in "nation state". Na

The Irish are a nation, a people with a unique language and identity. That is what OP is referring to. It the same definition of nation as in "nation state". Namely a nation state is a state with one dominant people. Germany, Japan, Thailand, Ireland, are nation states. US, UK, are by their nature not nation states. So yes, North Ireland represents a nation seperate to the English, the Welsh, or the Scotts.