What does adamant mean?
The definition of adamant
Ad”a*mant, n.
Etym: [OE. adamaunt, adamant, diamond, magnet, OF. adamant, L. adamas, adamantis, the hardest metal, fr. Gr. adamare to love, be attached to, the word meant also magnet, as in OF. and LL. See Diamond, Tame.]

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.