Estoppel

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.

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

A legal principle preventing someone from arguing something contrary to a previous claim.

a rule of evidence whereby a person is barred from denying the truth of a fact that has already been settled