To prevent by legal means

Usage examples of estop.

In other words, that parties by entering into contracts may not estop the legislature from enacting laws intended for the public good.

Having told him that she had a divorce, she will be estopped to take advantage of her chicanery.

Having resorted to fraud to lead Garvin Hastings to think she had secured a divorce, she is now estopped to falsify her own utterances.