Another word for arbitrary
Capricious; said of people
willful, capricious, self-assertive, frivolous, injudicious, wayward, offhand, erratic, impulsive, inconsistent, crotchety, irresponsible, opinionated, supercilious, self-willed, whimsical, unreasonable, irrational, toplofty*.
Without adequate determining principle: said of actions or ideas
subjective, unscientific, unreasonable, unpredictable, capricious, random, chance, temporary, unpremeditated, irrational, motiveless, unaccountable, superficial, whimsical, fanciful, freakish, determined by no principle, depending on the will alone, optional, uncertain, inconsistent, discretionary, subject to individual will, half-baked*.
Another word for arbitraryadjective
Determined or marked by whim or caprice rather than reason:capricious, whimsical. See surprise
Based on individual judgment or discretion:discretionary, judgmental, personal, subjective. See opinion, surprise
Having and exercising complete political power and control:absolute, absolutistic, autarchic, autarchical, autocratic, autocratical, despotic, dictatorial, monocratic, totalitarian, tyrannic, tyrannical, tyrannous. See over, politics