The Collaborative International Dictionary of English v.0.48:

Breadth \Breadth\ (br[e^]dth), n. [OE. brede, breede, whence
   later bredette, AS. br[=ae]du, fr. br[=a]d broad. See
   Broad, a.]
   [1913 Webster]
   1. Distance from side to side of any surface or thing;
      measure across, or at right angles to the length; width.
      [1913 Webster]

   2. (Fine Arts) The quality of having the colors and shadows
      broad and massive, and the arrangement of objects such as
      to avoid to great multiplicity of details, producing an
      impression of largeness and simple grandeur; -- called
      also breadth of effect.

            Breadth of coloring is a prominent character in the
            painting of all great masters.        --Weale.
      [1913 Webster]