Levity I: Gravity-Silent Regimes and the Structural Denial of Gravitational Outcomes

Gravity is universally present in physical systems, yet its observable role varies widely, appearing dominant in some regimes and effectively silent in others. This work introduces levity as a regime-level classification describing situations in which gravitational interaction is present but structurally inexpressible due to prior constraint of admissible degrees of freedom. Levity is not a force, repulsive interaction, or modification of gravitational law. Rather, it names regimes in which boundary conditions, circulation, geometry, or constraint saturation deny the pathways through which gravity would ordinarily organize motion or structure. We define levity precisely, distinguish it from force balance and dynamical cancellation, and classify several observed forms, including boundary-denied, circulation-dominated, and constraint-saturated regimes. The concept is presented as a descriptive and organizing framework compatible with established gravitational theory, intended to clarify why gravity may appear silent without being absent. Quantitative formulation and application are deliberately deferred.