There are a number of synonymous terms for the phrase "base coin," referring to the basic currency unit of a given system. Some examples include "unit of account," "primary denomination," and "fundamental monetary unit." Other possible phrases might include "baseline currency," "core coin," or "standard unit." The concept of the base coin is an important one in any monetary system, as it provides the basis for all other transactions and valuations within that system. Understanding the synonyms for this term can help clarify discussions of economic policy and financial systems alike.