In law and government, appropriation (from Latin appropriare, "to make one's own", later "to ") is the act of something for its application to a particular usage, to the exclusion of all other uses.

An appropriation bill or running bill or supply bill is a legislative motion (bill) that authorizes the government to spend money. It is a bill that sets money aside for specific spending. In most democracies, approval of the legislature is necessary for the government to spend money.