From Proto-Balto-Slavic *śwīnas, from a very old borrowing into Indo-European, probably borrowed at the same time as the word for “iron”. It was probably influenced or contaminated by Hittite 𒅆𒉌𒋾 (šiniti, “copper”), and by Proto-Indo-European *ḱwey- (“to shine, white, light”) (> Proto-Baltic *šwei-, *šwi-). Cognates include Lithuanian švi̇̀nas, Old East Slavic свиньць (svinĭcĭ) (Russian свине́ц (svinéc)); the word is also probably related to Ancient Greek κύανος (kúanos, “bluish metal”), from Hittite [script needed] (kuwannan-, “precious stone, copper, blue”).