adjective, noun, plural -trar⋅ies.| 1. | subject to individual will or judgment without restriction; contingent solely upon one's discretion: an arbitrary decision. |
| 2. | decided by a judge or arbiter rather than by a law or statute. |
| 3. | having unlimited power; uncontrolled or unrestricted by law; despotic; tyrannical: an arbitrary government. |
| 4. | capricious; unreasonable; unsupported: an arbitrary demand for payment. |
| 5. | Mathematics. undetermined; not assigned a specific value: an arbitrary constant. |
| 6. | arbitraries, Printing. (in Britain) peculiar (def. 9). |