Asklemmy

Its my understanding that in Spanish, "American" refers to anyone from the Americas. In some languages/countries, the Americas are taught as 1 continent (Europe, Asia, Africa, Australia, Antarctica, and America), so a person from any country in the Americas would be called "American".

In most English speaking countries, we are taught that there are 7 continents, and north and south America are separate continents. In that context, you wouldn't really use a term to refer to people from both continents. It's similar to how, as a spaniard, I could not call you "eurasian", i would just say "european". In English, you would then have to refer to people as either "north american" or "south american".

In practice, we do refer to people from south America as "south american", but north america usually gets divided into "central american" and "caribbean", which only leaves the US, Canada, and Mexico.

People from Mexico and Canada have obvious demonyms, while the USA does not. "Gringo" also applies to Canadians (and it's specifically referring to non-spanish speaking european americans), so it doesn't really work as a demonym. "Yankee" doesn't really work, either, because it only applies to a subset of people from the US, so it's similar to calling everyone from Great Britain "English".

I haven't met any primarily English speaking residents of the americas with any problem with people from the US being called "american".

Usonian also works.

USian

We say "USA" for the country and "US-American" for the people. Those arrogantly misusing the name of the continent can get rekt.

Do you not have a term in Spanish?

If y'all use yank, yankee, or gringo, they're all fine.

But, American is fine too. If you're using English, everyone will know what you mean. It isn't like it hasn't been the term used in English for at least a century.

Here the thing. If you're referring to someone from one of the two/three americas, you specify north, central and south. That depends a little on whether you consider all three as discrete areas, or not, but that's the norm in English.

If you want to refer to all people from the americas at once, Americans is also fine. Context will carry which way you're using it. English is fairly easy to make contextual indicators like that.

An example: "oh, Americans love their flag". Which americans are we talking about? The ones with a specific American flag. Which, the statement isn't universally true, it's just an example.

If you aren't using English, it doesn't matter at all, use whatever terminology is the norm in that language.

The reason it doesn't matter is that there really isn't an "American" people in the continental sense. The cultures of the continents don't even have a unifying effect, though you do have some connection between Spanish speaking vs Portuguese, vs native, vs English, etc. The language links in South America are much more significant than the fact that they live on the same continent.

Any time you'd be referring to the entire Americas, or the peoples of them, you'd specify that because there's not a single American continent.

One nation out of all of them being america really isn't a difficulty in conversation. It's a non issue.