Source : Webster's Revised Unabridged Dictionary (1913)

Orderly \Or"der*ly\, n.; pl. {Orderlies}.
   1. (Mil.) A noncommissioned officer or soldier who attends a
      superior officer to carry his orders, or to render other
      service.

            Orderlies were appointed to watch the palace.
                                                  --Macaulay.

   2. A street sweeper. [Eng.] --Mayhew.