A caveat is a warning or notice that is provided to an individual or entity before they take action. The term comes from the Latin word "caveat," which means "let him beware". The term has a range of usages that are common in finance, law, and other areas. Here are some examples of how the term is used:

• In Australian property law and other jurisdictions using the Torrens title system, a caveat is a warning that someone other than the owner claims some right over or nonregistered interest in the property).
• In finance and law, when someone adds a caveat to a contract or a legal situation, they effectively add a warning that the other party should be alerted to the possibility of a dangerous or undesirable circumstance if they proceed any further.
• In probate proceedings, a caveat is a formal notice to a judicial officer requesting the officer to suspend a specific action until the party has received an opportunity to be heard on the matter.
• In general usage, a caveat can be any kind of warning or admonition.

Overall, a caveat is a way to provide advance warning or caution to someone before they take action.