Nummus (Greek: νοῦμμος, noummos), plural nummi (νοῦμμοι) is a Latin term meaning "coin", but used technically by modern writers for a range of low-value copper coins issued by the Roman and Byzantine empires during Late Antiquity. It comes from the Greek nomos via its Western Doric form noummos, which was used to describe a coin in some parts of southern Italy. The word was also used during the later years of the Roman Republic and the early Empire, either as a general word for a coin, or to describe the sestertius, which was the standard unit for keeping accounts.