Source : Webster's Revised Unabridged Dictionary (1913)

Quadroon \Quad*roon"\, n. [F. quarteron, or Sp. cuarteron. See
   {Quarter} a fourth part, and cf. {Quarteron}.]
   The offspring of a mulatto and a white person; a person
   quarter-blooded. [Written also {quarteron}, {quarteroon}, and
   {quateron}.]

Source : WordNet®

Quadroon
     n : an offspring of a Mulatto and a White parent; a person who
         is one-quarter Black