- Made of adamant, or having the qualities of adamant; incapable of being broken, dissolved, or penetrated
- 1674, John Milton, Paradise Lost, Book I, lines 44–49:
- Him the Almighty Power
- Hurld headlong flaming from th' Ethereal Skie
- With hideous ruine and combustion down
- To bottomless perdition, there to dwell
- In Adamantine Chains and penal Fire,
- Who durst defie th' Omnipotent to Arms.
- 1837 Thomas Carlyle, The French Revolution: A History
- For two hours they stand; Bouillé's sword glittering in his hand, adamantine resolution clouding his brows[.]
- 1984, Gayle Rubin, "Thinking Sex" in Carole S. Vance, Pleasure and Danger: Exploring Female Sexuality (Boston: Routledge and Kegan Paul), 267-319.
- Sex law is the most adamantine instrument of sexual stratification and erotic persecution.
- Like the diamond in hardness or luster.
incapable of being broken
like a diamond
adamantine f pl