What's the adjective for arbitration? Here's the word you're looking for.
Included below are past participle and present participle forms for the
verbs arbiter, arbitrage and arbitrate which may be used as adjectives within certain contexts.
arbitrary
(usually of a decision) Based on individual discretion or judgment; not based on any objective distinction, perhaps even made at random.
“What was the point of studying the random and arbitrary changes to which words, like all other earthly phenomena, were subject?”
“They came to the arbitrary conclusion that only alkali-resistant weeds would grow here.”
“Instead of making an arbitrary decision to increase the proposed volume, the general manager should inquire what would be necessary in order to plan for a specified increase.”