Source : Webster's Revised Unabridged Dictionary (1913)

Nuance \Nu`ance"\, n. [F.]
   A shade of difference; a delicate gradation.

Source : WordNet®

nuance
     n : a subtle difference in meaning or opinion or attitude;
         "without understanding the finer nuances you can't enjoy
         the humor"; "don't argue about shades of meaning" [syn: {nicety},
          {shade}, {subtlety}, {refinement}]