detective (n.)

"侦探，职业是调查需要信息的事情，特别是关于罪犯，并获取对他们的证据"，1828年，缩写自 detective police，来自 detective（形容词）"适合或擅长侦查"（在1828年之前）； 参见 detect + -ive。

His duties differ from those of the ordinary policeman in that he has no specific beat or round, and in that he is concerned with the investigation of specific cases, or the watching of particular individuals or classes of offenders, rather than with the general guardianship of the peace, and does not wear a distinguishing uniform. [Century Dictionary, 1897]

他的职责与普通警察不同，因为他没有特定的巡逻区域，他关注的是特定案件的调查，或者是特定个人或类别的罪犯的监视，而不是一般的维护和平，也不穿着有区别的制服。[世纪词典，1897年]