intr.v. frat·er·nized, frat·er·niz·ing, frat·er·niz·es
1. To associate with others in a friendly and informal way.
2. To associate on friendly terms with an enemy or opposing group, often in violation of discipline or orders.
3. To associate on friendly terms with one's superiors or subordinates, often in violation of policy.
[French fraterniser, from Medieval Latin frāternizāre, from Latin frāternus, fraternal; see FRATERNAL.]
frat′er·ni·zation (-nĭ-zāshən) n.
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.