The Collaborative International Dictionary of English v.0.48:

Homography \Ho*mog"ra*phy\, n.
   1. That method of spelling in which every sound is
      represented by a single character, which indicates that
      sound and no other.
      [1913 Webster]

   2. (Geom.) A relation between two figures, such that to any
      point of the one corresponds one and but one point in the
      other, and vise versa. Thus, a tangent line rolling on a
      circle cuts two fixed tangents of the circle in two sets
      of points that are homographic.
      [1913 Webster]