sex·cen·te·nar·y (sĕk-sĕntə-nĕr′ē, sĕk′sĕn-tĕnə-rē)
Relating to 600 or to a 600-year period.
n. pl. sex·cen·te·nar·ies
A 600th anniversary or its commemoration.
[From Latin sexcentēnī, six hundred each : sex, six; see SEX- + centēnī, a hundred each (from centum, hundred; see dek in the Appendix of Indo-European roots).]
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.