Introduction: The purpose of this study was to investigate the relationship between the polysemy of one of the verb prefixes of the Persian language using a cognitive approach. With the cognitive semantics approach, the verb prefixes have their own meanings that add the meanings to the host’ s verb, and, in fact, by combining with it, a verb with a new meaning is created. The prefix “ forou” is one of the most prevalent verb prefixes in Persian, which, by joining different verbs, forms a kind of radial semantic structure. In this article, we analyze the meanings of the “ forou” prefix from a cognitive perspective. Methods: First, all the preceding verbs with the prefix “ forou” were retrieved from the book “ Culture of Speech” (Sokhan) and then analyzed according to the cognitive semantic concepts, Polysemy Categorization and Schema. Accordingly, by specifying the radial category of this prefix, the Prototypical meaning, the semantic network and the structure of this prefix were determined in the form of a radial category. Finally, in order to analyze the semantic network of this prefix, the spatial interactions of the trajector (TR) and the landmark (LM) were used. Results: The results obtained from the analyses indicate that the prototypical meaning of this prefix is “ down and below” , and its semantic networks, which include several groups, are: reduction, humiliation, fixity and pause, degradation, etc. Also, all semantic meanings are associated with the main meaning. For example, the meaning of “ down” in the concepts of reduction, humiliation, is interrupted. Conclusion: With studing the prefix “ Forou” in terms of a cognitive semantics approach, we found that the cognitive approach, in addition to the different meanings of a prefix and its applications in different contexts, it proves the conceptual relationships between these meanings. Therefore, it provides a better analysis of semantics of prefixs compared with traditional approaches.