The article presents a careful analysis of the idea of the “open texture” of empirical concepts and the problems of verification in the way that they were formulated by Friedrich Waismann. The idea of the “open texture” means for Waismann a certain type of a linguistic indeterminacy or a sort of lack of definition, which must be distinguished from, and linked to, another types like vagueness or ambiguity. It is shown that empirical statements are not conclusively verifiable for two different reasons: the incompleteness of description of the material object and the open texture of the terms involved. We cannot conclusively verify statements in which the empirical concepts are used, because we cannot define these concepts in an exhaustive way because of their open texture. Thus, the definition of the concept will be incomplete. Waismann's approach to definition plays here a key role, and it is directly related to the open texture of concepts. The author proposes interpreting the open texture as an immanent prop