homography

 That method of spelling in which every sound is represented by a single character, which indicates that sound and no other.  [1913 Webster]

 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]