Etymology

From Proto-Balto-Slavic *kirsnos, from Proto-Indo-European *kr̥snós ‎(“black”). Cognates include Old Prussian kirsnan ‎(“black”), Old Church Slavonic чрънъ ‎(črŭnŭ, “black”) and Sanskrit कृष्ण ‎(kṛṣṇá, “black”).