A thought about the term “third world”. By the way, Third World and third world are both correct spellings.
I think it’s a vague and rather silly term. Why? Because virtually no one can correctly and accurately tell you: What exactly defines a First World country? What is a Second World country? Is there a Fourth World country?
I know respected writers who don’t know, and say: “Gosh, never thought about it…” But everyone knows Third World country means poor. How poor? Are there official lists? Not every person in a “poor” country is poor. And in a first world country like the US, not even 5% of Americans are “rich” (however “rich” is defined). Why not find a more specific and deadly accurate term?