Merriam-Webster Collegiate Dictionary - officer

 I. noun  Etymology: Middle English, from Anglo-French, from Medieval Latin officiarius, from Latin officium  Date: 14th century  1.  a. obsolete agent  b. one charged with police duties  2. one who holds an office of trust, authority, or command the ~s of the bank chief executive ~  3.  a. one who holds a position of authority or command in the armed forces; specifically commissioned ~  b. the master or any of the mates of a merchant or passenger ship  II. transitive verb  Date: 1670  1. to furnish with ~s  2. to command or direct as an ~