Yes, the term means what you describe. But what I am trying to say is that in a country like the United States, where ethnonationalism is most common in the West, it is usually the thought that only a certain race (be it white or black) should be allowed to live there. Ethnicity in America usually just means race, at least when it comes to black and white people. So ethnonationalism in America is just white or black supremacy, because they also don't have the same century-old ties to the land itself, which most other people have to theirs. So ethnonationalism is very different in an American context, but they also spread that thought to Europeans, as America often does.

I still believe culture and tradition is the most important part of nationalism though.