1. Relating to or composed of right angles.
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.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.