Estoppel

Webster's Dictionary of the English Language

·noun The agency by which the law excludes evidence to dispute certain admissions, which the policy of the law treats as indisputable.

II. Estoppel ·noun A stop; an obstruction or bar to one's alleging or denying a fact contrary to his own previous action, allegation, or denial; an admission, by words or conduct, which induces another to purchase rights, against which the party making such admission can not take a position inconsistent with the admission.