early 14c., "one who holds an office" (originally a high office), from Old French oficier "officer, official" (early 14c.), from Medieval Latin officarius "an officer," from Latin officium "a service, a duty" (see office). The military sense is first recorded 1560s. Applied to petty officials of justice from 16c.; U.S. use in reference to policemen is from 1880s.
例文
1. He was returned to prison in 1977 for impersonating a police officer .
彼は1977年に警察官になりすまして再投獄された。
2.Secret Service officer Robin Thompson spoke on behalf of his colleagues.
捜査官ロビン?トンプソンが同僚を代表して発言した。
3.The Night Duty Office was ready to clock off.
夜勤の署員がカードを打って退勤する準備をしている。
4.He got permission from his commanding officer to join me.
彼は指揮官の許可を得て私と合流した。
5.One of the apprentices made an insulting remark to a passing officer .