Abbott-Smith Manual Greek Lexicon
χαλκός (G5475)
5 χαλκός , -οῦ, ὁ [in LXX chiefly for נְחֹשֶׁת ;] copper : I Co 13:1 , Re 18:12 ; by meton., of copper coin, Mt 10:9 , Mk 6:8 12:41 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain