/ Dictionary / Index A adamantine: Meaning and Definition of Find definitions for: ad•a•man•tine Pronunciation: (ad"u-man'tēn, -tin, -tīn), [key] — adj. utterly unyielding or firm in attitude or opinion. too hard to cut, break, or pierce. like a diamond in luster. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: adamantine (Thesaurus) adamantane Adamawa-Eastern Related Content Daily Word Quiz: ontiguous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language