tri·sect (trīsĕkt′, trī-sĕkt)
tr.v. tri·sect·ed, tri·sect·ing, tri·sects
To divide into three equal parts.
trisec′tion (trīsĕk′shən, trī-sĕk-) n.
trisec′tor (trīsĕk′tər, trī-sĕk-) n.
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 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.