adamantium

From adamant +‎ -ium.

adamantium (uncountable)

1. A fictional metal that is indestructible or nearly so.
   • 1941 June, Jameson, Malcolm, “Devil's Powder”, in Astounding Science-Fiction‎, volume 27, number 4, Street & Smith:

     It was a bullet. It was a small slug of adamantium, the toughest and hardest of all metals, crammed to capacity with the terrific explosive feroxite and would burst instantly on any reasonable heavy impact.

   • 1969 July, Thomas, Roy, “Betrayal”, in Avengers, volume 1, number 66, Marvel Comics:

     It's imperative that these experiments be concluded with haste! The military must know the potential of this new adamantium at once! Even the President is standing by!

adamantium (not comparable)

1. Made of adamantium.
   • 2004, Asher, Neal, Gridlinked, Macmillan, →ISBN, page 324:

     'We knew the egg was adamantium. Not much else could have been learnt.'

adamantium

1. genitive masculine/feminine/neuter plural of adamāns

Unadapted borrowing from English adamantium.

adamantium m (uncountable)

1. (fiction) adamantium (fictional indestructible metal)