| a rapidly rotating funnel-shaped cloud extending downward from the base of a cumulonimbus cloud, which, if it touches the surface of the earth, is a tornado or waterspout. |
| Main Entry: | funnel cloud |
| Part of Speech: | n |
| Definition: | a funnel-shaped cloud descending from a towering cumulus or cumulonimbus that, if it reaches the ground, becomes a tornado |
| Usage: | science |