Estop
Estop , transitive verb
[Old French estoper to stop, plug, close, French étouper, Late Latin stuppare to close with tow, obstruct, from Latin stuppa tow, oakum, compare Greek sty`pph. Compare Stop.]
(Law) To impede or bar by estoppel.
A party will be estopped by his admissions, where his intent is to influence another, or derive an advantage to himself.