1. extremely hard and unbreakable
Usage: literary
2. unyielding and inflexible in attitude or opinion
Usage: formal

Examples

• The hero’s adamantine shield could not be pierced by any weapon.
• Her adamantine resolve helped her overcome every obstacle.
• The ancient fortress was built with adamantine walls that stood for centuries.
• His adamantine refusal to negotiate frustrated his opponents.
• The adamantine chains binding the prisoner were said to be unbreakable.
• She maintained an adamantine silence despite hours of questioning.