adamant

1. A stone imagined by some to be of impenetrable hardness; a name given to the diamond and other substance of extreme hardness; but in modern minerology it has no technical signification. It is now a rhetorical or poetical name for the embodiment of impenetrable hardness. Opposed the rocky orb Of tenfold adamant, his ample shield. Milton. 2. Lodestone; magnet. [Obs.] "A great adamant of acquaintance." Bacon. As true to thee as steel to adamant. Greene.

Source: Webster's Revised Unabridged Dictionary (1913), United States public domain. See methodology for full licensing detail. Word validity for game play may differ from any official game dictionary.