term:

Merger Clause

merger clause n

: a clause in a contract stating that the contract is a complete statement of the agreement and supersedes any prior terms, representations, or agreements whether made orally or in writing [merger clauses do not apply to subsequent modifications "J. J. White and R. S. Summers"]

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