The Collaborative International Dictionary
Geodetical
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.
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.
Wiktionary
geodetical
a. of, or relating to geodesy; geodesic