discretionary spending

Short definition from Wiktionary

Noun

1. 1
   The amount or portion of a person's or group's expenditures which is used for non-essential or voluntary disbursements; the amount or portion of one's expenditures which one may make as one sees fit.
2. 2
   The action of making such expenditures.
3. 3
   US government expenditures which are subject to annual review and authorization by Congress, as distinct from expenditures authorized by existing laws.