释义：任意的，随机的，不按照规定，规矩的，武断的，专政的。Based on random choice or personal whim, rather than any reason or system
Synonyms: capricious, random, chance
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.
Even though arbitrary comes from a word meaning “judge” (arbiter), that doesn’t mean judges are always fair. Calling a decision-maker arbitrary is usually a negative thing, suggesting the person is making rules based on whim rather than justice. A coach who selects starting players arbitrarily isn’t strictly applying a rule; he could just be picking names out of a hat.