bronze n.

"yellow malleable alloy metal, harder than copper," Old English bræs "brass, bronze," originally any alloy of copper, in England usually with tin (this is now called bronze), later and in modern use an alloy of roughly two parts copper to one part zinc. A mystery word, with no known cognates beyond English. Perhaps akin to French brasser "to brew," because it is an alloy. It also has been compared to Old Swedish brasa "fire," but no sure connection can be made. Yet another theory connects it with Latin ferrum "iron," itself of obscure origin.

Words for "brass" in other languages (such as German Messing, Old English mæsling, French laiton, Italian ottone) also tend to be difficult to explain. As brass was unknown in early antiquity (it was well-known to Strabo, 1c., but not mentioned by Homer), the use of the English word in Bible translations, etc., likely means "bronze." The Romans were the first to deliberately make it.

When works of Greek and Roman antiquity in 'brass' began to be critically examined, and their material discriminated, the Italian word for 'brass' (bronzo, bronze) came into use to distinguish this 'ancient brass' from the current alloy. [OED]

Rhetorically or figuratively it was the common type of hardness, durability, or obduracy since late 14c. The meaning "effrontery, impudence, excessive assurance" is from 1620s. The slang sense of "high officials" is first recorded 1899, from their insignia. The meaning "brass musical instruments of a band" is from 1832.

malleable metallic element, noted for its peculiar red color, tenacity, malleability, and electric conductivity, late Old English coper, from Proto-Germanic *kupar (source also of Middle Dutch koper, Old Norse koparr, Old High German kupfar), from Late Latin cuprum, contraction of Latin Cyprium (aes) "Cyprian (metal)," after Greek Kyprios "Cyprus" (see Cyprus).

Ancient Greek had khalkos "ore, copper, bronze;" an old IE word for "ore, copper, bronze" is retained in Sanskrit ayah, Latin aes. Latin aes originally was "copper," but this was extended to its alloy with tin (see bronze), and as this was far more extensively used than pure copper, the word's primary sense shifted to the alloy and a new word evolved for "copper," from the Latin form of the name of the island of Cyprus, where copper was mined (the alchemists associated copper with Venus).

Aes passed into Germanic (which originally did not distinguish copper from its alloys) and became English ore. In Latin, aes was the common word for "cash, coin, debt, wages" in many figurative expressions. Chemical symbol Cu is from cuprum.

As "a copper coin," from 1580s; as "a vessel made of copper," 1660s. The adjective, "of or resembling copper," is from 1570s; the verb, "to cover with copper" is from 1520s.