adamantine

Synonym of adamant.; 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.

Synonym of adamant.; Incapable of being broken, dissolved, or penetrated; impenetrable, unbreakable.figuratively

• adamantine bonds adamantine chains

Synonym of adamant.; Difficult to defeat or prevail over; unshakable, unyielding.figuratively

• For two hours they stand; [François Claude Amour, marquis de] Bouillé's sword glittering in his hand, adamantine resolution clouding his brows; […]
• He [William III of England] was proved by every test; […] by the imminent and constant risk of assassination, a risk which has shaken very strong nerves, a risk which severely tried even the adamantine fortitude of [Oliver] Cromwell.

Synonym of adamant.; Of a person: refusing to change one's mind; obstinate, stubborn.figuratively

• 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.

Synonym of adamant.; Having the quality of attracting or drawing; attractive, magnetic.figurativelyobsolete

• Embravvne your ſoft-skind encloſure vvith Adamantine duſt, that it may dravve nothing but ſteele vnto it.
• Hail, adamantine Steel! magnetic Lord! / King of the provv, the plovvſhare, and the ſvvord! / True to the pole, by thee the pilot guides / His ſteady helm amid the ſtruggling tides, […]

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.

Synonym of adamantium (“a fictional metal which is indestructible or nearly so”).alsoattributiveuncountable