The quality of being absolutely firm, unwilling to change one's mind, or impossible to persuade.
From 'adamant' (from Greek 'adamas,' diamond/unconquerable) + '-ness' (quality). The noun form emerged in English in the 16th century to describe the abstract quality of extreme stubbornness.
Adamantness is what you'd call someone's refusal to budge—like a diamond that won't crack. History shows that adamantness has started wars and saved lives depending on what someone was being stubborn about!
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