orthogonal in WordNet English dictionary

1. not pertinent to the matter under consideration
   "an issue extraneous to the debate"; "the price was immaterial"; "mentioned several impertinent facts before finally coming to the point"
   extraneous  immaterial  impertinent  orthogonal 
   
2. having a set of mutually perpendicular axes; meeting at right angles
   "wind and sea may displace the ship's center of gravity along three orthogonal axes"; "a rectangular Cartesian coordinate system"
   orthogonal  rectangular 
   
3. statistically unrelated
   orthogonal