1. circulatory motion in liquid or gas: circulatory movement in a liquid or gas, resulting from regions of different temperatures and different densities rising and falling in response to gravity
2. heat transfer leading to cloud formation: heat transfer within the atmosphere involving the upward movement of huge volumes of warm air, leading to subsequent condensation and cloud formation
[Mid-19th century. < late Latin convection-< Latin convehere "bring together" < vehere "carry"]
