adamantium

From adamant +‎ -ium.

adamantium (uncountable)

1. A fictional metal that is indestructible or nearly so.

   Synonym: adamantine

   • 1941 June, Malcolm Jameson, “Devil's Powder”, in Astounding Science-Fiction‎^[1], 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, Roy Thomas, “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!

• (imaginary desirably hard material): unobtainium

adamantium (not comparable)

1. Made of adamantium.
   • 2004, Neal Asher, 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.

• Hyphenation: a‧da‧man‧ti‧um

adamantium m (uncountable)

1. (fiction) adamantium (fictional indestructible metal)