Source : Webster's Revised Unabridged Dictionary (1913)

Truckler \Truc"kler\, n.
   One who truckles, or yields servilely to the will of another.

Source : WordNet®

truckler
     n : someone who humbles himself as a sign of respect; who
         behaves as if he had no self-respect [syn: {apple
         polisher}, {bootlicker}, {fawner}, {groveller}, {groveler},
          {ass-kisser}]