look up any word, like smh:
 
5.
the rarest of ALL elements unexistent everywhere in today's world you'll NEVER be able to aquire some nobody has any at all it's undoable
as the chief procurator here, I've searched the net, scoured the collectors inventories boggled my mind far and wide, but struck out bro your frosted, translucent, illumuinated silk-ma~che 12vdc /12ft long stringer of dingo balls must have been made of unobtainium they're nowhere to be found damn!
by grzly February 27, 2009
 
1.
An imaginary unavailable material used humourously to solve otherwise impossible problems; an item of unaffordable price.
Of course, it would have to be made of pure unobtainium to work.
by Peter Baird August 16, 2003
 
2.
any nonexistent material
A ship like that would have been made of unobtainium
by The Return of Light Joker April 01, 2010
 
3.
The fictional element of a (person's) personality which makes them out of reach for either friendship, courtship, or a relationship.
She is 100% un-obtainium. She will never get involved with you.
by Orlando Orlando Furioso August 21, 2010
 
4.
Term used by engineers and hobbyists to define a material that is extremely hard to obtain.
-Space rockets are mostly made of unobtainium.
-There are so many conflicts in Africa due to the presence of unobtainium in the ground.
-Your CNC machine will crash only when you machine this one piece of unobtainium. Of course, you do not have enough to make a new piece.

A piece of shitanium that got broken will magically turn into unobtainium if you look for a replacement (Thus making it extremely expensive, even if you found one)
by MisterLebowski August 24, 2013
 
6.
James Cameron's autograph
James Cameron only gives his Unobtainium for fan money.
by Skyloop December 26, 2009
 
7.
Referring to a person, place or thing that will never happen.
"He took her out to dinner three times, but she turned out to be unobtainium."
by MontanaBlueDog December 18, 2009