1. Determined by chance, whim, or impulse, and not by necessity, reason, or principle: stopped at the first motel we passed, an arbitrary choice.
2. Based on or subject to individual judgment or preference: The diet imposes overall calorie limits, but daily menus are arbitrary.
3. Law Relating to a decision made by a court or legislature that lacks a grounding in law or fact: an arbitrary penalty.
4. Not limited by law; despotic: the arbitrary rule of a dictator.
[Middle English arbitrarie, from Latin arbitrārius, from arbiter, arbitr-, arbiter; see ARBITER.]
ar′bi·trari·ly (-trârə-lē) adv.
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.