1) An orthogonal projection 2) At right angles to each other 3) Extraneous 4) French word used in English 5) Immaterial 6) Impertinent 7) Irrelevant 8) Meeting at right angles 9) Statistically unrelated 1) Extraneous 2) Irrelevant 3) Perpendicular 4) Unrelated 
• (a.) Right-angled; rectangular; as, an orthogonal intersection of one curve with another.
At right angles to; independent of. Orthogonal curves are two families of curves with the property that each member of one family meets members of the other family at right angles.
applies to two non-zero vectors the scalar product of which is zero NOTE - In a real two- or three-dimensional space, orthogonal vectors are also called perpendicular.
At right angles to each other.
Or·thog'o·nal adjective [ Confer French orthogonal .] Right-angled; rectangular; as, an orthogonal intersection of one curve with another. Orthogonal projection . 
[adj] - having a set of mutually perpendicular axes
orthogonal 1. Having or determined by right angles; perpendicular. 2. An area of a computer display in which units of distance are the same horizontally and vertically so that there is no distortion.
Mutually perpendicular. See also: Perpendicular.
rectangular adjective 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`
an orthogonal projection. · Also,orthographic.pertaining to or involving right angles or perpendiculars:an orthogonal projection. · (of a system of real functions) defined so that the integral of the product of any two different functions is zero. · (of a system of complex functions) defined so that the integral of the product of a f...
[SAT terms] meeting at right angles