Siek and Taha  coined the term gradual typing to describe a technical approach to integrating static and dynamic typing within a single language that 1) puts the programmer in control of which regions of code are statically or dynamically typed, and 2) enables the gradual migration of code between the two typing disciplines. Since 2006, the term gradual typing has become quite popular but its meaning has become diluted to encompass anything related to the integration of static and dynamic typing. This dilution is partly the fault of the original paper, which provided an incomplete formal characterization of what it means to be gradually typed. In this talk I draw a crisp line in the sand, articulating a new formal property, named the gradual guarantee, that relates the behavior of programs that differ only with respect to the precision of their type annotations. I argue that the gradual guarantee provides important guidance for designers of gradually-typed languages. I survey the gradual typing literature, critiquing designs in light of the gradual guarantee. I report on a mechanized proof that the gradual guarantee holds for the Gradually-Typed Lambda Calculus.