It typically refers to the legislative designation of money for particular uses, in the context of a budget or spending bill.
In the Middle Ages in England the custom grew up of the monasteries reserving to their own use the greater part of the tithes of their appropriated benefices, leaving only a small portion to their vicars in the parishes.
[2] Regular appropriations bills are passed annually, with the funding they provide covering one fiscal year.
If Congress has not enacted the regular appropriations bills by the start of a new fiscal year, it can pass a continuing resolution, which continues the pre-existing appropriations at the same levels as the previous fiscal year (or with minor modifications) for a set amount of time.
In England and Wales, the Theft Act 1968 s 3(1) defines appropriation as "Any assumption by a person of the rights of an owner".