from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Impervious to pleas, appeals, or reason; stubbornly unyielding. See Synonyms at inflexible.
- n. A stone once believed to be impenetrable in its hardness.
- n. An extremely hard substance.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Firm; unshakeable; unyielding; determined.
- n. A rock or mineral held by some to be of impenetrable hardness; a name given to the diamond and other substances of extreme hardness.
- n. An embodiment of impregnable hardness.
- n. A magnet; a lodestone.
from the GNU version of the Collaborative International Dictionary of English
- n. A stone imagined by some to be of impenetrable hardness; a name given to the diamond and other substances of extreme hardness; but in modern mineralogy it has no technical signification. It is now a rhetorical or poetical name for the embodiment of impenetrable hardness.
- n. Lodestone; magnet.
from The Century Dictionary and Cyclopedia
- n. A name applied with more or less indefiniteness to various real or imaginary metals or minerals characterized by extreme hardness: as the diamond
- n. the natural opposite of the diamond
- n. a lodestone or magnet, and
- n. an anti-magnet.
- n. In general, any substance of impenetrable or surpassing hardness; that which is impregnable to any force.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- adj. impervious to pleas, persuasion, requests, reason
- n. very hard native crystalline carbon valued as a gem
From Middle English, a hard precious stone, from Old French adamaunt, from Latin adamās, adamant-, from Greek, unconquerable, hard steel, diamond; see demə- in Indo-European roots.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin adamantem, accusative singular form of adamās ("hard as steel"), from Ancient Greek ἀδάμας (adamas, "invincible"), from ἀ- (a-, "not") + δαμάζω (damazo, "I tame"). (Wiktionary)