Source : Webster's Revised Unabridged Dictionary (1913)

Trembler \Trem"bler\, n.
   1. Any of certain West Indian birds of the genera
      {Cinclocerthia} and {Rhamphocinclus}, of the family
      Mimid[ae].

   2. (Elec.) The vibrating hammer, or spring contact piece of a
      hammer break, as of the electric ignition apparatus for an
      internal-combustion engine.

Trembler \Trem"bler\, n.
   One who trembles.

Source : WordNet®

trembler
     n : one who quakes and trembles with (or as with) fear [syn: {quaker}]