"اسم المفعول" is a grammatical term in Arabic that refers to the noun form derived from a verb, indicating the subject that receives the action. It is often used to describe a person or thing that is affected by the action of the verb. For example, from the verb كتب (to write), the اسم المفعول is كاتب (writer), indicating someone who writes. In Arabic, اسم المفعول is typically formed by applying specific patterns to the root of the verb. These patterns can vary based on the verb's form and conjugation. Understanding اسم المفعول is essential for mastering Arabic grammar, as it helps in constructing meaningful sentences and conveying actions effectively.