adamant
Pronunciation:
/ˈæ.də.mænt/noun
Definitions
An imaginary rock or mineral of impenetrable hardness; a name given to the diamond and other substances of extreme hardness.
An embodiment of impregnable hardness.
A lodestone.
adjective
Definitions
(said of people and their conviction) Firm; unshakeable; unyielding; determined.
(of an object) Very difficult to break, pierce, or cut.