English 'diamond' descends from Greek 'adámas' (unconquerable), from 'a-' (not) + 'damân' (to tame), from PIE *demh₂- (to tame) — literally 'the untameable stone,' making 'diamond' and 'tame' opposites derived from the same ancient root.
A precious stone consisting of pure crystallized carbon, the hardest naturally occurring substance.
From Old French 'diamant,' from Medieval Latin 'diamantem' (accusative of 'diamas'), an alteration of Latin 'adamantem' (accusative of 'adamās'), from Greek 'adámas' (ἀδάμας), meaning 'unconquerable, invincible,' and by extension 'the hardest metal or stone.' Greek 'adámas' is formed from 'a-' (not) + 'damân' (to tame, to conquer), from PIE *demh₂- (to tame, to domesticate). The initial 'a-' was lost through
'Diamond' and 'tame' are etymological opposites from the same root. Greek 'adámas' (un-tameable) gave 'diamond'; English 'tame' comes directly from PIE *demh₂- (to tame) via Proto-Germanic. A diamond is literally 'the untameable stone' — and 'adamant' (unyielding) preserves the original Greek