Translation

恣意的な / 任意の / 理由のない

Meaning

Arbitrary means based on personal choice, chance, or whim rather than a clear reason, rule, or principle. In criticism, it often means unfair because no good reason is given.

Examples

• その罰金の額は恣意的に見えました。
  The amount of the fine seemed arbitrary.
• 委員会は恣意的な決定を避けようとしました。
  The committee tried to avoid arbitrary decisions.