We don't have synonyms for arbitray yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are arbitrary, arbitrate and arbitrage.
""The Russian trials were Stalin's purges, with which he attempted to consolidate his power. Like most people in the West, I believed these show trials to be the arbitrary acts of a cruel dictator." ()"
""The Russian trials were Stalin's purges, with which he attempted to consolidate his power. Like most people in the West, I believed these show trials to be the arbitrary acts of a cruel dictator." ()"