Tornado
Tornado , noun
[From Sp. or Portuguese tornar to turn, return, Latin tornare to turn, hence, a whirling wind. The Sp. & Portuguese tornada is a return. See Turn.]
(Meteorology) A violent whirling wind; specifically (Meteorology), a tempest distinguished by a rapid whirling and slow progressive motion, usually accompaned with severe thunder, lightning, and torrents of rain, and commonly of short duration and small breadth; a small cyclone<-- twister -->.