The end-of-the-year movie rush is upon us, when the studios roll out their high-prestige projects. I've been thinking about words related to two major movies of the season: Up in the Air (now in theaters), adapted from the novel of the same name by Walter Kirn, and Avatar (coming soon!), the sci-fi extravaganza from James Cameron of Titanic fame.

The protagonist of Up in the Air, Ryan Bingham (played by George Clooney) is a corporate downsizer who constantly travels the country laying off employees at different companies. He has no real home in the traditional sense, and no real friends either, but he feels quite at home in the place-less places of air travel. In Kirn's novel, the character dubs his home "Airworld":

I call it Airworld; the scene, the place, the style. My hometown papers are USA Today and The Wall Street Journal. The big-screen Panasonics in the club rooms broadcast all the news I need, with an emphasis on the markets and the weather. My literature — yours, too, I see — is the best seller or the near-best seller, heavy on themes of espionage, high finance and the goodness of common people in small towns... Airworld is a nation within a nation, with its own language, architecture, mood and even its own currency — the token economy of airline bonus miles that I've come to value more than dollars. Inflation doesn't degrade them. They're not taxed. They're private property in its purest form.

Though Kirn's concept of "Airworld" is brilliantly expressed on the screen through director Jason Reitman's fine adaptation, the term itself, curiously, has not made the transition from book to film. That's a shame, since it's such a handy designation and deserves a wider audience. Some travel bloggers have been inspired by Kirn's coinage and have used "Airworld" since the novel's publication in 2001. The bloggers at World Hum seem to be particularly enamored with the term. When JetBlue opened a new terminal called T5 at John F. Kennedy International Airport (with all the latest amenities, including free wi-fi!), World Hum's Rob Verger celebrated by spending a whole day there, in a series he titled "24 Hours in Airworld." (That sounds a bit like the plot of another airport-centric movie, The Terminal starring Tom Hanks.)

As for Avatar, the most linguistically interesting aspect of this 3-D blockbuster will undoubtedly be the alien language of Na'vi, developed by Paul Frommer, a professor of clinical management communication at the University of Southern California. In last Sunday's "On Language" column in the New York Times Magazine, I place Frommer's work on Na'vi in the context of other sci-fi languages crafted by linguists, most notably Marc Okrand's wildly successful creation of Klingon for the Star Trek franchise.

It remains to be seen, however, if Na'vi will take off like Klingon, with its own subculture of fans. Both languages require mastering some rather exotic phonetics. Just as Klingon devotees must practice their lateral affricates, potential Na'vi speakers will need to learn the language's ejective consonants. Na'vi's explosive ejectives pack a particular punch in words like skxawng, meaning "moron," an epithet that Frommer says became popular among the crew on the Avatar set. (You can hear Frommer pronouncing some sample Na'vi dialog, ejectives and all, as a bonus feature in the online version of my "On Language" column.)

But there's at least one English word in Cameron's film that is worthy of note: unobtainium, the name of the precious mineral that humans are mining on the distant world of Pandora, home of the Na'vi. The word (also spelled unobtanium) is far from new: it's the tongue-in-cheek label for a stock feature of science fiction, and by using the term Cameron seems to be paying homage to the genre's tradition of imaginatively improbable substances.

As Paul Dickson notes in his new Dictionary of the Space Age, unobtainium has a history in the aerospace industry predating its sci-fi usage. The first known appearance is in Woodford Heflin's Interim Glossary, Aero-Space Terms, a February 1958 publication of the Air University of the U.S. Air Force, where the word is tagged "humorous or ironical." Here is Heflin's full definition:

A substance having the exact high test properties required for a piece of hardware or other item of use, but not obtainable whether because it theoretically cannot exist or because technology is insufficiently advanced to produce it.

Cameron has been chasing his own unobtainium ever since Titanic. Heflin's definition could just as easily fit the sophisticated effects that the director sought for Avatar: for years, the technology was "insufficiently advanced" to produce the alien world of Pandora. Now that Cameron has finally obtained his unobtainium, we'll see if the quarry was worth the pursuit.

Have you come across any noteworthy words or phrases in other movies of the past year? Let us know in the comments below!