IIRC, there's only one English speaking South American country, and the Amazon doesn't run through it. You could argue that 'some people in some countries' speak English, which is true, but the same is also true that a large amount of folks in the US speak Spanish, yet we don't try to claim .EU.
The Amazon is not just the river and the basin it is also,most importantly, the rainforest which belongs to 8 countries (9 if you count France). You have Portuguese, Spanish, Dutch, English, and French plus several creole languages there. Guess whose language is the best one for a common denomination?
That's an interesting point. I'm not saying you're wrong, just posing the following for thought: If a country/language picks a name for a place, that that place doesn't use, who owns it so to speak? That is, who 'owns' the word Germany? And by own I mean, makes some claim to it. It's hard for me as American perhaps because the 'lingua franca' is my native language. For example, I feel no sense of ownership of the words 'Estados Unitos', or Meiguo(sp?), and see them as belonging to other countries. Food for thought...
Portuguese? Spanish?
"Amazon" is "Amazonas" in both Spanish and Portuguese. Guayana is the only majority English speaking country I can find in South America, and it's hundreds of miles from the Amazon river at its closest point.
In Portuguese it's way more common to refer to the region as "Amazônia" (the rainforest) than "Amazonas" (the river). "Amazonas" hardly represents the Brazilian side.
Regardless, English is the lingua franca of the Internet and that's the reason why geographical terms in English matter.
Well, Amazonas is also the name of the largest Brazilian state by area and one of the largest subdivisions in the world.
It is not "Guayana" it is Guyana. And the Amazon rainforest covers part of Guyana and Suriname too for that matter. And even France. So you have at least 5 European languages plus several creoles.