Wiktionary
n. 1 (context economics English) 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 The action of making such expenditures. 3 (context US government finances English) US government expenditures which are subject to annual review and authorization by Congress, as distinct from expenditures authorized by existing laws.
Wikipedia
In public finance, discretionary spending is government spending implemented through an appropriations bill. This spending is an optional part of fiscal policy, in contrast to entitlement programs for which funding is mandatory.
In the United States, discretionary spending refers to spending set on a yearly basis by decision of Congress. Such spending is usually authorized by Congress in another act. Provisions of an appropriations act that authorize spending are earmarks. When an authorization act also appropriates funds, it is called mandatory spending.
Usage examples of "discretionary spending".
Apart from wasting the enormous amount of capital invested in all the other millions of signs and billboards, the amounts of discretionary spending power still available must be infinitesimal.