Fuzzy
A fuzzy concept is a concept of which the boundaries of application can vary considerably according to context or conditions, instead of being fixed once and for all.[1] This means the concept is vague in some way, lacking a fixed, precise meaning, without however being unclear or meaningless altogether.[2] It has a definite meaning, which can become more precise only through further elaboration and specification, including a closer definition of the context in which the concept is used.