1. based on random choice or personal whim, rather than any reason or system
2. using unlimited power without considering what is fair or right

Examples

• The teacher’s grading seemed arbitrary and unfair.
• The king made arbitrary decisions without consulting anyone.
• The deadline appears arbitrary since there’s no clear reason for choosing that date.
• Students complained about the arbitrary dress code rules.
• The judge’s ruling was not arbitrary but based on legal precedent.
• Management’s arbitrary changes to the schedule frustrated employees.