Source : Webster's Revised Unabridged Dictionary (1913)

Ferris wheel \Fer"ris wheel\
   An amusement device consisting of a giant power-driven steel
   wheel, revolvable on its stationary axle, and carrying a
   number of balanced passenger cars around its rim; -- so
   called after G. W. G. Ferris, American engineer, who erected
   the first of its kind for the World's Columbian Exposition in
   Chicago in 1893.

Source : WordNet®

Ferris wheel
     n : rotating mechanism consisting of a large upright wheel with
         suspended seats that remain upright as the wheel turns;
         provides a ride at an amusement park