A more thorough explanation:

A caveat is a formal notice to a judge or other judicial officer requesting that they suspend a specific action until the party has had an opportunity to be heard on the matter. This is often used in probate proceedings when a party wants to challenge the validity of a will.

Let's say that John's father passed away and left a will that gives everything to John's sister, Jane. John believes that the will is not valid and wants to challenge it. He can file a caveat with the court, which will prevent the court from initiating the administration of the estate until John has had a chance to be heard.

Each state has its own rules about caveats. For example, in Florida, the probate court must notify the party who filed the caveat of any pending probate proceedings and allow them to challenge the will before it can be admitted to probate.

Caveat can also mean a warning or admonition. For example, the legal maxim "caveat emptor" means "let the buyer beware." This means that buyers are responsible for making sure that they are getting what they pay for and should be cautious when making purchases.