n. An object found or obtained for free, particularly material for an art, craft, or construction project.
2013
A self-described "atypical artist," Phyllis Hartley of East Falmouth is making her own waves by creating art out of what she calls "obtainium" — interesting objects she happens upon in the woods, on the beach, along the roadside, the landfill or even in her neighbor’s yard.
2012
"The Obtainium Fairies" is a children’s book that Sikes has written to share the experience of his childhood, where parents and kids invented their own fun together using obtainium (whatever they could find or had at hand).
1994 (earliest)
One SRL crew member says that they like to put shows on in Europe because there is a lot of "Obtainium" there. What's Obtainium?: "Something that is easily obtained, easily liberated, or gotten for free."
A close cousin to this term is unobtainium , which has been used by engineers since the 1950s to refer to any fictional or impossible material that would be ideal for solving a problem or allowing a design to function. In the movie Avatar, Unobtainium was the name given to the rare mineral that the humans were mining on the planet Pandora.