This paper introduces the Meaning Equation (Meaning = Context × Coherence) and the Drift Equation (Drift = Optimization – Context) as a minimal framework for understanding how meaning emerges and erodes across language, culture, organizations, and AI. It formalizes the role of context dimensions (temporal, relational, spatial, symbolic) in sustaining meaning, and describes drift as the hollowing of meaning when optimization strips away context. The framework extends traditions in semiotics, information theory, and organizational sensemaking while engaging recent debates in AI about semantic drift, fidelity, and alignment. Applications include language models, cultural trends, and organizational fragility, offering a portable shorthand for diagnosing the dynamics of meaning and drift. Part of Reality Drift framework (2023-2026) by A. Jacobs.