Source : Webster's Revised Unabridged Dictionary (1913)

Spending \Spend"ing\, n.
   The act of expending; expenditure.

   {Spending money}, money set apart for extra (not necessary)
      personal expenses; pocket money. [Colloq.]

Source : WordNet®

spending money
     n : cash for day-to-day spending on incidental expenses [syn: {pocket
         money}, {pin money}]