Meaning of adamantine

Definition of adamantine

(adj) consisting of or having the hardness of adamant
having the hardness of a diamond
impervious to pleas, persuasion, requests, reason; "he is adamant in his refusal to change his mind"; "Cynthia was inexorable; she would have none of him"- W.Churchill; "an intransigent conservative opposed to every liberal tendency"

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