(of an action, a decision, a rule, etc. 行动、决定、规章等 not seeming to be based on a reason, system or plan and sometimes seeming unfair 任意的；武断的；随心所欲的 The choice of players for the team seemed completely arbitrary. 看来这个队的队员完全是随意选定的。 He makes unpredictable, arbitrary decisions. 他做的决定难以预料，主观武断。
Oxford Collocations Dictionaryverbs- be
- seem
- completely
- entirely
- purely
- …
- (formal)
using power without limits and without considering other people 专横的；专制的 the arbitrary powers of officials 官员的专制权力
Word Originlate Middle English (in the sense ‘dependent on one's will or pleasure, discretionary’): from Latin arbitrarius, from arbiter ‘judge, supreme ruler’, perhaps influenced by French arbitraire.