The Collaborative International Dictionary of English v.0.48:

Faller \Fall"er\, n.
   1. One who, or that which, falls.
      [1913 Webster]

   2. (Mach.) A part which acts by falling, as a stamp in a
      fulling mill, or the device in a spinning machine to
      arrest motion when a thread breaks.
      [1913 Webster]

WordNet (r) 3.0 (2006):

faller
    n 1: a person who fells trees [syn: lumberman, lumberjack,
         logger, feller, faller]
    2: a person who falls; "one of them was safe but they were
       unable to save the faller"; "a faller among thieves"