Source : Webster's Revised Unabridged Dictionary (1913)

Subsistence Department \Sub*sist"ence De*part"ment\ (Mil.)
   A staff department of the United States army charged, under
   the supervision of the Chief of Staff, with the purchasing
   and issuing to the army of such supplies as make up the
   ration. It also supplies, for authorized sales, certain
   articles of food and other minor stores. It is commanded by
   any officer of the rank of brigadier general, called
   commissary general, and the department is popularly called
   the {Commissary Department}.