STEP Greek Lexicon: ὑάκινθος

ὑακίνθος, -ου, ό

[in LXX chiefly for תְּכֵלֶת ;]

hyacinth;

__(a) in cl., a flower, prob. the dark blue iris;

__(b) in late writers, a precious stone of the same colour, perhaps the sapphire: Rev.21:20 (Phil., FlJ, al.).†

(AS)