The Collaborative International Dictionary of English v.0.48:

Orthographic \Or`tho*graph"ic\, Orthographical
\Or`tho*graph"ic*al\, a. [Cf. F. orthographique, L.
   orthographus, Gr. ?.]
   1. Of or pertaining to orthography, or right spelling; also,
      correct in spelling; as, orthographical rules; the letter
      was orthographic.
      [1913 Webster]

   2. (Geom.) Of or pertaining to right lines or angles.
      [1913 Webster]

   Orthographic projection or Orthogonal projection, that
      projection which is made by drawing lines, from every
      point to be projected, perpendicular to the plane of
      projection. Such a projection of the sphere represents its
      circles as seen in perspective by an eye supposed to be
      placed at an infinite distance, the plane of projection
      passing through the center of the sphere perpendicularly
      to the line of sight.
      [1913 Webster]