Third World
From Tardis Wiki, the free Doctor Who reference
On Earth, the "Third World" included Africa and Latin America. While undercover at the Pharm, "Samantha Jones" was asked by Plummer if she had visited the Third World; she claimed that she did not but would get round to it. Plummer insinuated that she might be more susceptible to "exotic tropical disease[s]" were she to visit these places. (TV: Reset)
Behind the scenes
Originating in the Cold War as a signifier of wartime neutrality, the term "Third World" has come to be synonymous with "developing countries", ie. colonised nations now in relative poverty, in part due to neocolonialism.