1. (

• extraneous ,
• immaterial ,
• impertinent ,
• orthogonal

) 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" ;

2. (

• orthogonal

) statistically unrelated ;

3. (

• orthogonal ,
• rectangular

) 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" ;