derogation n[Latin derogatio partial abrogation of a law, from derogare to detract from the force of (a law)]
: a taking away or detraction from something (as the force of a law) [the executive was without power to act in of international law "Jules Lobel"]
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.