unobtanium

Noun

unobtainium (countable and uncountable, plural unobtainiums)

1. (humorous) A fictional material or component which, if it existed, would enable one to easily solve a hard problem.
   • Thus the invention of high temperature fuels will enable us to consider cores which are radiation cooled; such cores would be surrounded by large tanks (cooled by water) which in turn would be penetrated by beam holes. The beam holes themselves would probably have to be made of "unobtanium". (This...1962, Charles N. Kelber, “Research Reactors”, in Earl W. Phelan, editor, Current Trends in Nuclear Power: A Symposium Sponsored by the University of Arizona in Cooperation with Argonne National...

   Synonyms:

   handwavium

2. (humorous) An especially rare material or component that is outrageously expensive or otherwise almost impossible to get hold of.
   • The vacuum furnace has been greatly improved and today we are melting titanium, zirconium, high alloy steels and other materials which are remarkably free of impurities and possess improved properties. These high performance metals are used in turbojet engines, missiles and atomic reactors. […] We...1956, Aerospace, volumes 11-12
3. (humorous) A high technology component that is extremely expensive.
   • [D]oes our device require any technologies that we're not likely to be able to develop, buy, or otherwise obtain? This unobtainable content is sometimes called unobtanium, and can take various forms: [...] Things that exist, but don't exist for us. If Acer needs a beautiful custom 15″ LCD panel...2015 August 10, Alan Cohen, “Preliminary Planning: Can This be a Success?”, in Mike Loukides, Meghan Blanchette, editors, Prototype to Product: A Practical Guide for Getting to Market, Sebastopol...