adamantinus
From LSJ
ὑμῖν ἔξεστι εὐδαίμοσι γενέσθαι → to you it is permitted to be joyful, it is permitted to be happy, it is permitted to be fortunate, vobis licet esse beatis
Latin > English (Lewis & Short)
ădămantĭnus: a, um, adj., = ἀδαμάντινος>,
I hard as steel, etc., adamantine: saxa, Lucr. 2, 447: duritia, Plin. 37, 11, 73. —Hence poet., extremely hard, inflexible, invincible: clavi, Hor. C. 3, 24, 5: tunica, id. ib. 1, 6, 13: juga, Prop. 3, 9, 9; cf. aënus.
