Source : Webster's Revised Unabridged Dictionary (1913)

Officer \Of"fi*cer\, n. [F. officier. See {Office}, and cf.
   {Official}, n.]
   1. One who holds an office; a person lawfully invested with
      an office, whether civil, military, or ecclesiastical; as,
      a church officer; a police officer; a staff officer. ``I
      am an officer of state.'' --Shak.

   2. (U. S. Mil.) Specifically, a commissioned officer, in
      distinction from a warrant officer.

   {Field officer}, {General officer}, etc. See under {Field},
      {General}. etc.

   {Officer of the day} (Mil.), the officer who, on a given day,
      has charge for that day of the quard, prisoners, and
      police of the post or camp.

   {Officer of the deck}, or {Officer of the watch} (Naut.), the
      officer temporarily in charge on the deck of a vessel,
      esp. a war vessel.