n. pl. rad·i·ces (rădĭ-sēz′, rādĭ-) or ra·dix·es
1. Biology A root or point of origin.
2. Abbr. rad. Mathematics The base of a system of numbers, such as 2 in the binary system and 10 in the decimal system.
[Latin rādīx, root; see wrād- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. 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.