What does solidus mean?
A solidus is chiefly an ancient gold coin introduced by the Roman emperor Constantine in the early fourth century. These coins became important instruments of imperial trade and diplomacy, and their minting continued under the Byzantine Empire. In a separate, typographic sense, a solidus is an oblique stroke resembling a forward slash, though modern usage more often calls this mark a slash. The words solid and consolidate ultimately share the same Latin root: solidus meant “solid,” “whole,” or “compact,” and developed through Old French into the English word for a firm, substantial material. A solidus is therefore useful for recognizing both a major artifact of ancient monetary history and an older name for a familiar punctuation mark.
nounA gold coin used in the late Roman and Byzantine periods. The term is also used for a typographic solidus, an oblique stroke resembling a forward slash.
- A gold coin of the late Roman Empire, introduced in the early fourth century and continued in the Byzantine Empire.
- An oblique typographic mark, especially the forward slash used to separate or indicate alternatives.
"The auction house sold a rare Byzantine solidus to a private collector."
"The museum's collection includes a late Roman solidus minted at Constantinople."
"Replace the solidus between the two categories with a semicolon."
Plural solidi is preferred when referring collectively to the ancient coins. The form soliduses is also attested, especially in general or typographic contexts.
"The hoard contains dozens of solidi from successive Byzantine emperors."
Before euros and dollars, Rome had the solidus: a prestigious gold coin that carried imperial authority across the ancient world.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does solidus come from?
The English word comes through Latin from solidus, an adjective meaning “solid,” “compact,” or “complete.” The same Latin term was also applied to a gold coin, especially under the late Roman and Byzantine Empires. Its typographic use developed from the currency's name: the oblique stroke of a coin-inscription convention came to be called a solidus and is now recognized as a diagonal slash.
Related word forms
How solidus is actually used
In numismatic contexts, the plural is usually solidi. The typographic sense is now less common because the mark is more often called a slash.