ESTOPPEL
estoppel
(noun) a rule of evidence whereby a person is barred from denying the truth of a fact that has already been settled
Source: WordNet® 3.1
Etymology
Noun
estoppel (countable and uncountable, plural estoppels)
(common law) A legal principle in the law of equity that prevents a party from asserting otherwise valid legal rights against another party because of conduct by the first party, or circumstances to which the first party has knowingly contributed, make it unjust for those rights to be asserted.
Source: Wiktionary
Es*top"pel, n. Etym: [From Estop.] (Law)
(a) 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.
(b) The agency by which the law excludes evidence to dispute certain
admissions, which the policy of the law treats as indisputable.
Wharton. Stephen. Burrill.
Source: Webster’s Unabridged Dictionary 1913 Edition