资料来源 : Webster's Revised Unabridged Dictionary (1913)

Flag \Flag\, n. [Cf. LG. & G. flagge, Sw. flagg, Dan. flag, D.
   vlag. See {Flag} to hang loose.]
   1. That which flags or hangs down loosely.

   2. A cloth usually bearing a device or devices and used to
      indicate nationality, party, etc., or to give or ask
      information; -- commonly attached to a staff to be waved
      by the wind; a standard; a banner; an ensign; the colors;
      as, the national flag; a military or a naval flag.

   3. (Zo["o]l.)
      (a) A group of feathers on the lower part of the legs of
          certain hawks, owls, etc.
      (b) A group of elongated wing feathers in certain hawks.
      (c) The bushy tail of a dog, as of a setter.

   {Black flag}. See under {Black}.

   {Flag captain}, {Flag leutenant}, etc., special officers
      attached to the flagship, as aids to the flag officer.

   {Flag officer}, the commander of a fleet or squadron; an
      admiral, or commodore.

   {Flag of truse}, a white flag carried or displayed to an
      enemy, as an invitation to conference, or for the purpose
      of making some communication not hostile.

   {Flag share}, the flag officer's share of prize money.

   {Flag station} (Railroad), a station at which trains do not
      stop unless signaled to do so, by a flag hung out or
      waved.

   {National flag}, a flag of a particular country, on which
      some national emblem or device, is emblazoned.

   {Red flag}, a flag of a red color, displayed as a signal of
      danger or token of defiance; the emblem of anarchists.

   {To dip, the flag}, to mlower it and quickly restore it to
      its place; -- done as a mark of respect.

   {To hang out the white flag}, to ask truce or quarter, or, in
      some cases, to manifest a friendly design by exhibiting a
      white flag.

   {To hang the flag} {half-mast high or half-staff}, to raise
      it only half way to the mast or staff, as a token or sign
      of mourning.

   {To} {strike, or lower}, {the flag}, to haul it down, in
      token of respect, submission, or, in an engagement, of
      surrender.

   {Yellow flag}, the quarantine flag of all nations; also
      carried at a vessel's fore, to denote that an infectious
      disease is on board.

资料来源 : WordNet®

flag officer
     n : a senior naval officer above the rank of captain