What is the characteristic of a funnel cloud?

A funnel cloud is specifically defined as a violent rotating column of air that descends from a cloud but does not make contact with the ground. This characteristic is crucial because it distinguishes a funnel cloud from a tornado, which does touch the ground and can cause significant damage. Funnel clouds are typically associated with severe thunderstorms and tornadoes, where conditions allow for the development of such rotating air columns. The identification of a funnel cloud as not being in contact with the surface helps meteorologists assess potential tornado activity, as a funnel cloud can quickly develop into a tornado if it descends further and touches the ground. Overall, the key feature of a funnel cloud is its formation and behavior in the atmosphere, indicating strong convective activity without direct ground interaction.