The Collaborative International Dictionary of English v.0.48:

Geodetic \Ge`o*det"ic\, Geodetical \Ge`o*det"ic*al\, a.
   Of or pertaining to geodesy; obtained or determined by the
   operations of geodesy; engaged in geodesy; geodesic; as,
   geodetic surveying; geodetic observers.
   [1913 Webster]

   Geodetic line or Geodetic curve, the shortest line that
      can be drawn between two points on the elipsoidal surface
      of the earth; a curve drawn on any given surface so that
      the osculating plane of the curve at every point shall
      contain the normal to the surface; the minimum line that
      can be drawn on any surface between any two points.
      [1913 Webster]