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In numismatic, the Argenteus (from the Latin Argenteus) was a silver coin produced in the Roman empire beginning from the monetary reform of Diocleziano in 294 up to around 310. It was similar as weight and fineness to the denarius of the time of Nerone. The coin was produced to a theoretical weight of a 1/96 of the Roman pound (that is of around 3 grams), as suitable of the Roman number XCVI on the reverse of the coin.
The word Argenteus, that means 'of silver' in Latin, you/he/she is used for the first time by Plinio the Old one in his/her Naturalis historia in the sentence "nummus argenteus" (silver coin). The historian of the fourth century Ammiano Marcellino uses the same expression, there is not however an indication that this is the official name for a denomination. The Historia August it uses the sentence to refer to quite a lot fictitious coins.