Source : Webster's Revised Unabridged Dictionary (1913)

Dancer \Dan"cer\, n.
   One who dances or who practices dancing.

   {The merry dancers}, beams of the northern lights when they
      rise and fall alternately without any considerable change
      of length. See {Aurora borealis}, under {Aurora}.

Source : WordNet®

dancer
     n 1: a performer who dances [syn: {professional dancer}]
     2: a person who participates in a social gathering arranged for
        dancing (as a ball) [syn: {social dancer}]