Abarim Publications' online Biblical Greek Dictionary
The noun σιδηρος (sideros) means iron. It's unclear where it comes from but the Latin noun sidus means star or rather stellar constellation, or even the entire heavenly vault. These words in turn are rumored to be related to the Latin verb sudo, to sweat or melt, from the same Proto-Indo-European root "sweyd-", to sweat, that gave English its word sweat.
How an ancient word for sweat became attached to iron isn't clear, except perhaps to say that iron requires an unusual hot furnace to extract and smelt, meaning that the Iron Age was directly preceded by an age during which ancient engineers tried to understand fire, blasting and other such advanced furnace technology. Gold and bronze are yellow, which is an attribute of sunlight. Iron, like silver, is white (metal-white), which is an attribute of stars. Throughout the world, the singular sun is considered royal and divine (our words monk and monarch come from mono, alone, and solo comes from sol, sun), whereas stars are always the dynamic masses of a human republic or heavenly host (see our article on the noun αστηρ, aster, for more on stars). Golden sunlight and silver starlight relate like the two clauses of the Great Command (gold: love God — silver: love your neighbor).
In the Bible, gold represents the great unified and unchanging natural law, whose study is open to everyone but the talent of only a select few. Nowadays these talented few use their knowledge of natural law to make iPhones and such. In antiquity they mostly made narratives that reflected these truths (Revelation 3:18). Silver represents the economy of perpetual communication; the clouds, rivers and oceans of conversation that purify words and mold ideas and sharpen minds (see for the cognitive equivalent of the hydrological cycle our article on the noun νεφελη, nephele, cloud). Bronze, another yellow metal and the first smelted one, represents intuition and artistic instinct (see our article on χαλκος, chalkos, bronze). And iron represents legislation (and more specifically, law enforcement: Genesis 4:22, Leviticus 26:19, Deuteronomy 4:20, 28:48, and so on) that comes from a human center of authority rather than God's gold or humanity's silver.
These four metals are of course most spectacularly arranged in the statue envisioned by Nebuchadnezzar and explained by Daniel (Daniel 2:31-33). The feet of the statue were made of iron mixed with clay (actually: baked clay or pottery; see Revelation 3:18 and Jeremiah 17:1), and the word used for clay is the Aramaic equivalent of the word חרש (harash), pottery, from the verb חרש (harash I), meaning to engrave in order to store data (hence also 2 Corinthians 4:7), as strikingly used in Job 2:8. This vision has baffled many, and here at Abarim Publications we don't know either but we guess that in this context the clay represents the industry of make-belief that is presently ruining humanity's trust-based institutions: anything from fiat currencies to propaganda and cover-ups.
Ancient engineers had been able to work iron for centuries before it finally surpassed bronze. That suggest that people began to use iron not when their engineers figured out how to do that, but when their warnings began to be ignored. The Hebrew word for iron is ברזל (barzel), which is of unclear origin, but which may have been adopted from a foreign language because it sounded like ברזי־לי (b'razi-lay), meaning "herein lies the wasting of...", or something to that extent.
Our noun σιδηρος (sideros), meaning iron, occurs in the New Testament in Revelation 18:12 only, but from it derives:
- The adjective σιδηρεος (sidereos), meaning iron or made from iron. This adjective is used 5 times; see full concordance.