Conlang flag - Image via WikipediaConlang (n.) - Slang term for constructed language, which is a language created for a specific purpose rather than one that evolves naturally from consensual public usage. Conlangs are often created for use in fictional settings, with classic examples including Tolkien's Elvish from the Lord of the Rings book series, or Star Trek's Klingon, created by linguist Marc Okrand. There are, however, conlangers -- creators and consumers of constructed languages -- that develop these fictional tongues strictly for amusement, separate from any attachment to a book, television, or movie series. Some geeks use conlangs to flesh out their favorite fictional worlds, and some conlangers are just fake language geeks.
I bring it up because: HBO has commissioned a conlang of the Dothraki language for its miniseries adaptation of George R. R. Martin's Song of Ice and Fire book series. Just chalk it up as yet another concession to the too-passionate-to-be ignored geek demographic.