Definition of arbitrary

The word "arbitrary" has its roots in Latin. The Latin word "arbitrum" means "judge" or "arbiter," and the adjective "arbitarius" means "belonging to a judge" or "judicial." From this, the Middle English word "arbitray" emerged, initially meaning "subject to the discretion of a judge" or "dependent on the judgment of a judge." Over time, the meaning of "arbitrary" shifted to encompass a broader sense of something being based on personal whim or caprice, rather than reason or necessity. Today, the word is commonly used to describe an action or decision that is subjective, unpredictable, or lacking in inherent logic.