ex·or·di·um (ĭg-zôrdē-əm, ĭk-sôr-)
n. pl. ex·or·di·ums or ex·or·di·a (-dē-ə)
A beginning or introductory part, especially of a speech or treatise.
[Latin, from exōrdīrī, to begin : ex-, intensive pref.; see EX- + ōrdīrī, to begin; see ar- in the Appendix of Indo-European roots.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 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.