unobtainium
Noun
Meaning
A fictional material or component which, if it existed, would enable one to easily solve a hard problem.
Synonym: handwavium
An especially rare material or component that is outrageously expensive or otherwise almost impossible to get hold of.
A high technology component that is extremely expensive.
Source: en.wiktionary.orgExamples
Another largely synonymous term is wishalloy, citation Chapter 8 although the sense is often subtly different in that a wishalloy usually does not exist at all, whereas unobtainium may merely be unavailable.
Frequent Sunday night/Monday morning host of Coast to Coast AM George Knapp usually opens his show mentioning unobtainium.
For instance, unobtainium is described as being stronger than helium, and lighter than air.
In the 1970s, bicycle magazines, such as Bike World, sometimes referred to exotic lightweight bicycle parts as being made of unobtainium, which, while expensive, were commercially obtainable.
The concept of unobtainium is often applied flippantly or humorously.
The properties of any particular unobtainium depend on the intended use.