Providing opportunities for students to express ideas in their own words is key to promoting authentic disciplinary engagement and robust conceptual understanding. In this article, we discuss our experiences and observations related to students' informal vocabulary in the context of a middle school probability unit. We noticed that students' informal naming provided critical glimpses into their conceptions and tensions about sample spaces. The use of student-suggested names also served to compress previous discussions and facilitate higher-level conceptual thinking in later conversations. We share our experiences with informal naming in one curricular context and conclude with perceived benefits to allowing space for student naming as a broader instructional practice.