Source : Webster's Revised Unabridged Dictionary (1913)

Guidon \Gui"don\, n. [F. guidon, It. guidone. See {Guide}, v.
   t.]
   1. A small flag or streamer, as that carried by cavalry,
      which is broad at one end and nearly pointed at the other,
      or that used to direct the movements of a body of
      infantry, or to make signals at sea; also, the flag of a
      guild or fraternity. In the United States service, each
      company of cavalry has a guidon.

            The pendants and guidons were carried by the officer
            of the army.                          --Evelyn.