The term "incremental cost" is often used in business and accounting to describe the additional cost of producing or selling one more unit of a product or service. However, there are several other synonyms that can be used interchangeably with this term. For example, "marginal cost" refers to the cost of producing one more unit of a product, while "variable cost" refers to the cost of materials used to produce each unit. "Direct cost" is another synonym that refers specifically to the expenses that are directly related to producing a product, such as labor and materials. Other synonyms include "incremental expense", "per unit cost" and "cost of production per unit".