In various works of Ibn Sina, there are a number of scattered topics about the subject of pleasure. One of those topics is the definition of pleasure that needs to be thoroughly reviewed in order to achieve a coherent vision. In this paper, we will explore two ways to investigate pleasure quiddity. One way is through the classification of the six definitions based on the discussion of which each definition is expressed under it, and the other one is by examining the terms used in the definitions. These two methods bring us closer to a better understanding of Avicenna's vision. The first way leads us to the conclusion that the structure of definitions differs according to its subject. With regard to various structures, Ibn Sina has introduced various definitions for various purposes. However, the investigation through the second method shows that Ibn Sina’s view of pleasure is a unitary and coherent viewpoint because, with the use of components such as "perception" and "proper" that constitute the core of all definitions, they have a lexical and conceptual harmony.