1. An extremely destructive funnel-shaped rotating column of air that passes in a narrow path over land.
2. A short-lived but severe windstorm, especially one that occurs on the West African coast.
3. A state of frenzied activity or intense emotion, or someone in such a state.
4. Etymology: from 1556, a navigator's word for violent windy thunderstorm in the tropical Atlantic, probably a borrowing from Spanish tronada, "thunderstorm", from tronar, "to thunder"; from Latin tonare, "to thunder".

Tornadoes occur chiefly during thunderstorms. If the tip of the funnel touches the ground, it can cause extensive damage.

A tornado becomes visible when a condensation funnel made of water vapor (a funnel cloud) forms in extreme low pressures, or when the tornado lifts dust, dirt, and debris upward from the ground.

A mature tornado may be columnar or tilted, narrow or broad; sometimes so broad that it appears as if the parent thundercloud itself had descended to ground level.