1. based on whim: based solely on personal wishes, feelings, or perceptions, rather than on objective facts, reasons, or principles an arbitrary decision
2. random: chosen or determined at random the arbitrary order of the entries
3. authoritarian: with unlimited power arbitrary government
4. law not according to rule: based on the decision of a judge or court rather than in accordance with any rule or law arbitrary arrest
[15th century. < Latin arbitrarius "uncertain, depending on the judgment of an arbiter" < arbiter "judge"]
