unobtainium n.

a hypothetical substance that would be highly desirable but is unrealized or unobtainable; a notional substance with exceptional or ideal properties

SF Encyclopedia

  • 1956 Marshall (Michigan) Evening Chronicle 27 Feb. 6/8

    Scientists are now working on a new metal to be used in making the noses on intercontinental ballistics missiles. The metal is so hard to come by that the scientists have devised a lugubriously-humorous name for it. They call it ‘unobtainium’.

  • 1958 W. A. Heflin Interim Glossary: Aero-Space Terms 33/2 page image

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

  • 1983 D. Brin Startide Rising (1995) 93 David Brin bibliography

    None of the other moons in the Kthsemenee system had the one attribute this one possessed: a core of almost one percent unobtainium. Already thirty of the Brothers' ships had landed, to begin construction of the Weapon.

  • 1992 Bicycling May 4/1 (advt.)

    The place was swarming with day-glo lycra-clad riders and zillion-dollar unobtanium wonder bikes.

  • 2007 J. Cameron Avatar (shooting script) 16

    On Selfridge’s desk is a magnetic base, and hovering in mid-air, in the invisible field, is a lump of METALLIC ROCK. Pure UNOBTANIUM. He grabs it and holds it up between thumb and forefinger, in front of Grace’s eyes. Selfridge This is why we're here. Unobtanium. Because this little gray rock sells for twenty million a kilo.

Research requirements

antedating 1956

Last modified 2020-12-16 04:08:47
In the compilation of some entries, HDSF has drawn extensively on corresponding entries in OED.