Estoppel-by-deed Definition

noun
(law) A legal doctrine under which a first party who purports to sell real property that the first party does not actually own to a second party must actually convey that property to the second party if the first party later acquires title to that property.
Wiktionary
(law, archaic) The doctrine that a party is bound to a claim which that party made in order to induce another party to act.
Wiktionary