diamonddiamond

Diamond comes from Old French diamant, from Late Latin diamās, probably an alteration of Latin adamās ‘adamant’, from Ancient Greek ἀδάμας ‘diamond; invincible’.

1. Ancient Greekc. 800–300 BCEἀδάμας¹adámās‘diamond; invincible’uncertain
2. Latinc. 75 BCE–200 CEadamās¹‘adamant; diamond’uncertain
3. Late Latinc. 200–600 CEdiamās¹
4. Old Frenchc. 842–1400diamant¹
5. Middle Englishc. 1150–1500dyamaunt¹
6. Englishearliest quotation 1720diamond¹

1. ¹ Wiktionary, English diamond
2. Earliest quotation in Wiktionary’s entry: 1720, Francis Nichols, Rudiments of Honour: “Elphingston. Pearl a Chevron Diamond between three Boars Heads…”.