The Collaborative International Dictionary of English v.0.48:

Tornado \Tor*na"do\, n.; pl. Tornadoes. [From Sp. or Pg.
   tornar to turn, return, L. tornare to turn, hence, a whirling
   wind. The Sp. & Pg. tornada is a return. See Turn.]
   A violent whirling wind; specifically (Meteorol.), 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.
   [1913 Webster]

WordNet (r) 3.0 (2006):

tornado
    n 1: a localized and violently destructive windstorm occurring
         over land characterized by a funnel-shaped cloud extending
         toward the ground [syn: tornado, twister]
    2: a purified and potent form of cocaine that is smoked rather
       than snorted; highly addictive [syn: crack, crack
       cocaine, tornado]

The Free On-line Dictionary of Computing (19 January 2023):

Tornado

    The software development environment
   previously distributed with VxWorks.

   (1996-11-29)