Definitions of estop
to apply the doctrine of estoppel to stop someone from doing something or from exercising a right. Estoppel is a principle that prevents someone from making actions, statements or promises that are the opposite of what that person has earlier said, promised or otherwise implied (=suggested without saying it directly) or done, or that go against a finding of a court of law, especially when this would result in loss or harm to another person.
Each party hereto is estopped from making a claim.