late Old English, verbal noun from spend (v.). Spending-money is from 1590s.
Entries linking to spending
spend v.
"to pay out or away" (money or wealth), Old English -spendan (in forspendan "use up"), from Medieval Latin spendere, a shortening of Latin expendere "to weigh out money, pay down" (see expend) or possibly of dispendere "to pay out." A general Germanic borrowing (Old High German spendon, German and Middle Dutch spenden, Old Norse spenna). In reference to labor, thoughts, time, etc., attested from c. 1300. Intransitive sense "exhaust, wear (oneself) out" is from 1590s (see spent).