The word "prorated" refers to the process of allocating an amount proportionally based on a certain factor, usually time or usage. For example, when expenses are split among multiple parties based on their share of the total usage or duration, they are said to be prorated. This often occurs in financial contexts, such as determining how much rent is owed for a partial month or how to divide costs among individuals based on their level of participation.
The term "prorate" comes from the Latin word "pro rata," which means "in proportion." It is derived from "pro," meaning "for," and "rata," the feminine form of "ratus," meaning "fixed or settled." The term entered English usage in the late 19th century.