Parol Evidence Rule
parol evidence rule n: a rule of document interpretation: parol evidence offered to contradict or modify a writing (as a contract or will) is not admissible when the writing is unambiguous or was intended to be a final expression of the author's wishes
Source: Merriam-Webster's Dictionary of Law ©1996. Merriam-Webster, Incorporated. Published under license with Merriam-Webster, Incorporated.