n. In physics, the power of conducting heat, electricity, or sound; the property of being conductive.n. In physiology, the power of a nerve to conduct an impulse.n. The thermometric conductivity of the atmosphere; the change in temperature of the atmosphere due to its calorimetric conductivity. It is equal to the latter divided by the specific heat of a unit volume, or by the product of the specific heat of a unit mass multiplied by the density of the gas. It is therefore a large quantity in the upper regions of the atmosphere.