term:

Special Act

special act n

: an act of a legislature that is not of general application in all territory subject to the legislative power but affects private persons or only part of a class of persons in the same situation or only part of a more general subject matter or is intended to apply only in a particular subdivision of the entire territory

Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.