From nchosheth; something made of copper, i.e. The copper serpent of the Desert -- Nehushtan.
see HEBREW nchosheth
H5180. Nechushtan
נְחֻשְׁתָּן proper name, feminine given to bronze serpent 2 Kings 18:4 probably = bronze-god (so Thes, see also BauSemitic Rel. i. 288; compare נְחשֶׁת נְחַשׁ 18:4; Numbers 21:9 (twice in verse) ); — chief arg. ag. this are vocalization of ᵐ5 Νεσθαλει, A ᵐ5L Νε(ε)σθαν, and comparative unimportance of material of which image was made; others think of נָחָשׁ serpent (NöZMG xlii (1888), 482 תן + נחשׁ, Kloon the passage יתן + נחשׁ); LagBN 188, 205 thinks loan-word
IV. נחשׁ (possibly √ of following, si vera lectio; but precise meaning uncertain; GeiUrschrift 392 compare Arabic [= goad, prick; a certain piece of perforated wood (Frey)], Late Hebrew נְחשֶׁת [bottom of vessel, LevyNHWB iii. 374]).