1. adamantium - Noun
2. adamantium - Adjective
English Wikipedia has an article on:adamantiumWikipedia
adamantium (uncountable)
A fictional metal that is indestructible or nearly so.
adamantium (not comparable)
Made of adamantium.
I grew up on comic books. 'X-Men' was my favorite team; Wolverine was my guy. At 8 years old, I dressed up as Wolverine with Adamantium claws that I made out of aluminum! Brian Tee
A foot-long apiece and coated in nigh unbreakable adamantium, they can cut through nearly anything and have allowed Wolverine to defeat all manner of opponents over the years including ones that he should have lost to. Source: Internet
Cable singlehandedly dispatched all of the X-Men, with Wolverine attacking him in a berserker rage, forcing Cable to reveal his own adamantium claws and revelation that he was a future incarnation of Wolverine. Source: Internet
Adamantium is something that can cause damage to Hulk. Source: Internet
Even having his adamantium skeleton ripped out couldn't keep the ol'Canucklehead down. Source: Internet
In the aforementioned Wolverine's adamantium skeleton was forcibly removed by Magneto in battle. Source: Internet