Source : Webster's Revised Unabridged Dictionary (1913)

Diabetes \Di`a*be"tes\, n. [NL., from Gr. ?, fr. ? to pass or
   cross over. See {Diabase}.] (Med.)
   A disease which is attended with a persistent, excessive
   discharge of urine. Most frequently the urine is not only
   increased in quantity, but contains saccharine matter, in
   which case the disease is generally fatal.

   {Diabetes mellitus} [NL., sweet diabetes], that form of
      diabetes in which the urine contains saccharine matter.

   {Diabetes insipidus} [NL., lit., diabetes], the form of
      diabetes in which the urine contains no abnormal
      constituent.

Source : WordNet®

diabetes mellitus
     n : diabetes caused by a relative or absolute deficiency of
         insulin and characterized by polyuria; "when doctors say
         `diabetes' they usually mean `diabetes mellitus'" [syn: {DM}]