- 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. - Lodestone; magnet.
Meaning of 'adamant' (Princeton's WordNet)
1 . adamant
[ s]
Meaning (1): - impervious to pleas, persuasion, requests, reason
Example in sentence:
an intransigent conservative opposed to every liberal tendency;
Cynthia was inexorable; she would have none of him;