The Collaborative International Dictionary of English v.0.48:
Spending \Spend"ing\, n. The act of expending; expenditure. [1913 Webster] Spending money, money set apart for extra (not necessary) personal expenses; pocket money. [Colloq.] [1913 Webster]WordNet (r) 3.0 (2006):
spending money n 1: cash for day-to-day spending on incidental expenses [syn: pocket money, pin money, spending money]