or·thog·o·nal 
(ôr-thŏgə-nəl)
(ôr-thŏgə-nəl)adj.
1. Relating to or composed of right angles.
2. Mathematics
a. Of or relating to a matrix whose transpose equals its inverse.
b. Of or relating to a linear transformation that preserves the length of vectors.
3. Very different or unrelated; sharply divergent: "Radical Islamists are ultimately seeking to create something orthogonal to our model of democracy" (Richard A. Clarke).
[From Greek orthogōnios : ortho-, ortho- + gōniā, angle; see genu-1 in the Appendix of Indo-European roots.]
or·thog′o·nali·ty (-nălĭ-tē) n.
or·thogo·nal·ly adv.