adamantive

Adjective

adamantine (comparative more adamantine, superlative most adamantine)

1. Made of adamant (“an unspecified mineral or rock of virtually impenetrable hardness”).
   • [A]t laſt appeer / Hell bounds high reaching to the horrid Roof, / And thrice threefold the Gates; three folds vvere Braſs, / Three iron, three of Adamantine Rock, / Impenitrable, impal'd vvith circling fire, / Yet unconsum'd.1667, John Milton, “Book II”, in Paradise Lost. […], London: […] [Samuel Simmons], and are to be sold by Peter Parker […]; [a]nd by Robert Boulter […]; [a]nd Matthias Walker, […], →OCLC, signature...
2. (figuratively) Incapable of being broken, dissolved, or penetrated; impenetrable, unbreakable.
   • adamantine bonds adamantine chains

   Synonyms:

   immovable, impregnable, indomitable, inextinguishable, inexpugnable, insuperable, insuppressible, insurmountable, invincible, inviolate

3. (figuratively) Difficult to defeat or prevail over; unshakable, unyielding.
   • For two hours they stand; [François Claude Amour, marquis de] Bouillé's sword glittering in his hand, adamantine resolution clouding his brows; […]1837, Thomas Carlyle, “Bouille at Metz”, in The French Revolution: A History […], volume II (The Constitution), London: Chapman and Hall, →OCLC, book II (Nanci), page 81
4. (figuratively) Of a person: refusing to change one's mind; obstinate, stubborn.
   • I thought this last information would soften the young man, but he was adamantine. He informed me that it was against all bank rules for a woman to draw from her husband's deposit without his order.1871 March, J[ane] L[ippit] Patterson, “My Lost Banker; a Story in Three Chapters. [Chapter] III.”, in The Ladies’ Repository: A Universalist Monthly Magazine for the Home Circle, volume XLV, Boston...

   Synonyms:

   intractable, obdurate, adamant, ardent, grim, untiring, bent on, bloody-minded, bullheaded, certain

5. (figuratively, obsolete) Having the quality of attracting or drawing; attractive, magnetic.
   • Embravvne your ſoft-skind encloſure vvith Adamantine duſt, that it may dravve nothing but ſteele vnto it.1593, Tho[mas] Nashe, Christs Teares Over Ierusalem. […], London: […] Iames Roberts, and are to be solde by Andrewe Wise, […], →OCLC, folio 34, recto
6. Like diamond in lustre; bright, lustrous, shiny; also, of a lustre: like that of a mineral with a high refractive index such as diamond.
   • Raspite, a new dimorphous form of lead tungstate, is found on some of the stolzite specimens as brownish or yellow monoclinic crystals with a strong adamantine lustre.1898 June, “Abstracts”, in H[enry] A[lexander] Miers, editor, The Mineralogical Magazine and Journal of the Mineralogical Society, volume XII, number 54, London: W[illia]m Dawson & Sons with the...

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