Convexion typically refers to the process or phenomenon of convection in a convex shape or context, although it is not a widely recognized term in scientific literature. Convection itself is the transfer of heat through the movement of fluids, where warmer, less dense areas rise and cooler, denser areas sink, creating a circulating flow. This concept can be observed in various natural and artificial systems, such as in weather patterns or heating systems. If "convexion" is meant in a different context, please provide more details for clarification.