Nowadays English is the most international of languages. Airline traffic control worldwide is conducted in English, and so is diplomacy, for the most part. But in the 1700s, the most international of languages was French. They didn’t have much use for air traffic control back then, but diplomacy was definitely conducted in French.
Diplomacy being partially concerned with the borders between nations, one of the words they found quite handy — in its English form — was “limitrophe,” which nowadays is pretty obscure. Limitrophe means a bordering country. For example Pakistan and Nepal are limitrophes of India.
The word goes back to the 1500s, as illustrated by Anthony Munday’s use in “Palmendos” from 1589: “He..became..famous through all the neyghbour Marches and limitrophes of Tharsus.” It’s remained in use, although not widely, and appeared in Raeff’s “Russia Abroad” in 1990: “The borders of the freshly created states to the west of Soviet Russia (Poland, the Baltic republics, and Romania, often called collectively the Limitrophes or Border States) included a native Russian population.“
It comes from the Latin word “limitrophus,” which referred to land reserved for supporting troops on the Roman frontiers. But the latter half of the word, “trophus,” comes instead from the Greek word “trophos”, which means “supporting”.
It’s even been used as recently as 2008, in the not-quite-best-seller “Ecosystem-based Management in the Colorado River Delta” by Karen Hae-Myung Hyun: “This stretch of international boundary, which the Colorado River forms, is known as the ‘limitrophe’.”
So if you want to impress some historically-minded diplomats at your next embassy cocktail party, casually tossing off “limitrophe” would probably do the trick, especially if they’ve spent any time in France! If you try it, by the way, the “e” is silent.