1. the quality of being based on random choice or personal whim rather than reason or system
2. the quality of being unreasonable or unfair in the use of authority or power

Examples

• The arbitrariness of the grading system frustrated many students.
• Citizens protested against the arbitrariness of the new regulations.
• The judge’s decision seemed to reflect arbitrariness rather than legal precedent.
• The arbitrariness of the selection process raised questions about fairness.
• She criticized the arbitrariness of the company’s promotion policies.
• The arbitrariness of nature was evident in the random distribution of the storm damage.