The adjective ' arbitrary ' has its roots in the Latin word 'arbitrarius,' which originally meant 'dependent on the judgment of an arbiter or judge.' It derives from 'arbiter,' meaning 'judge' or 'witness,' as mentioned earlier. Over time, the term evolved to encompass the idea of decisions made by personal judgment rather than adhering to established rules or principles. In English, ' arbitrary ' describes something that is based on individual discretion or personal opinion rather than ... Something that's arbitrary seems like it's chosen at random instead of following a consistent rule. Team members would dislike their coach using a totally arbitrary method to pick starting players. Arbitrary means based on chance or personal power, not reason or rules. Learn how to use this adjective in different contexts with synonyms, antonyms, and examples from the Cambridge Dictionary. Arbitrary definition: subject to individual will or judgment without restriction ; contingent solely upon one's discretion.. See examples of ARBITRARY used in a sentence.