adj.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.