What does billon mean?
Billon is a metallurgical and numismatic term for an alloy in which silver is mixed with a much greater quantity of a base metal, most commonly copper. Because the silver content is deliberately kept low, billon was inexpensive to produce, which made it the material of choice for small-change coinage throughout much of European history. Roman emperors of the later centuries struck increasingly debased billon denominations as their monetary system came under strain, and medieval and Renaissance rulers across France, the Low Countries, and elsewhere followed suit. The word also refers to the coins themselves when made of this alloy, so one may speak both of "billon" as a substance and of a "billon coin." Today the term survives chiefly in specialist contexts — auction catalogues, museum collections, and academic studies of coinage — where precision about a coin's metallic composition matters.
nounAn alloy of silver with a much larger proportion of a baser metal, especially copper, used historically for low-denomination coins. The term also denotes the debased currency itself struck from this alloy.
- An alloy of silver with a predominant proportion of copper or another base metal, used for making coins.
- Coinage struck from such an alloy.
"The medieval mint produced billon coins so heavily alloyed with copper that they tarnished almost black."
"The late Roman Empire issued billon denominations whose silver content steadily declined."
"Collectors prize the early billon issues of the French provinces for their historical interest rather than their precious-metal value."
Rarely pluralized in practice; the mass-noun sense referring to the alloy is usually left uninflected, though "billons" appears when counting distinct types of billon coinage.
"The catalogue lists several billons struck under different provincial mints."
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of billon
The word "billon" entered English from French in the seventeenth century, where it denoted base or debased metal used in coinage. Its ultimate origin lies in Medieval Latin, and it is generally connected with "bullion," both words relating to uncoined or base metal. The term has long been standard vocabulary in numismatics, describing the low-silver alloys that dominated everyday small change in many pre-modern economies.
How billon is actually used
A technical term of numismatics and metallurgy, encountered mainly in scholarly writing about coins and monetary history rather than in everyday speech.
Easily confused with billon
"Billion" is the number one thousand million, while "billon" is an alloy of silver and base metal used in coin-making.