1. 
[syn: gearing, gear, geartrain, power train, train]
The Collaborative International Dictionary of English v.0.48:
geartrain \gear"train`\ n.
   a connected set of rotating gears by which force is
   transmitted or motion or torque is changed.
   Syn: gearing, gears, power train, train.
        [WordNet 1.5]
WordNet (r) 3.0 (2006):
geartrain
    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]