Source : Webster's Revised Unabridged Dictionary (1913)

Bedpan \Bed"pan`\, n.
   1. A pan for warming beds. --Nares.

   2. A shallow chamber vessel, so constructed that it can be
      used by a sick person in bed.

Source : WordNet®

bedpan
     n : a shallow vessel used by a bedridden patient for defecation
         and urination