Wordnet 3.0
NOUN (1)
1. 
 wheelwork consisting of a connected set of rotating gears by which force is transmitted or motion or torque is changed; 
- Example: "the fool got his tie caught in the geartrain"[syn: gearing, gear, geartrain, power train, train]
WordNet (r) 3.0 (2006):
power train
    n 1: wheelwork consisting of a connected set of rotating gears
         by which force is transmitted or motion or torque is
         changed; "the fool got his tie caught in the geartrain"
         [syn: gearing, gear, geartrain, power train,
         train]