tornado

Definition

A violent wind in the form of a mobile, rapidly rotating, funnel cloud that has contacted the ground.

Etymology

From earlier English ternado, attested since the 1550s as a nautical term for a windy thunderstorm. From Spanish tronada (“thunderstorm”), from tronar (“to thunder”), from Latin tonō (“to thunder”), from Proto-Indo-European *(s)tenh₂- (“to thunder”). The o and r were reversed in English (metathesis) under influence of Spanish tornar (“to twist, to turn”), from Latin tornō (“to turn”).

Example Sentences

• "An extreme version of vorticity is a vortex. The vortex is a spinning, cyclonic mass of fluid, which can be observed in the rotation of water going down a drain, as well as in smoke rings, tornados and hurricanes."