Definitions of officer:

• noun:   a person authorized to serve in a position of authority on a vessel

  Example: "He is the officer in charge of the ship's engines"

• noun:   any person in the armed services who holds a position of authority or command

  Example: "An officer is responsible for the lives of his men"

• noun:   someone who is appointed or elected to an office and who holds a position of trust

  Example: "He is an officer of the court"

• noun:   a member of a police force

  Example: "It was an accident, officer"

• verb:   direct or command as an officer
• name:  A surname (rare: 1 in 100000 families; popularity rank in the U.S.: #18532)