a rule of evidence whereby a person is precluded from denying the truth of a statement of facts he or she has previously asserted
See also conclusion
Word origin
C16: from Old French estoupail plug, from estoper to stop up; see estop
estoppel in American English
(ɛˈstɑpəl)
noun
the barring of a person, in a legal proceeding, from making allegations or denials which are contrary to either a previous statement or act by that person or a previous adjudication