A more thorough explanation:

Metus (pronounced mee-tuh-s) is a Latin term used in Roman law. It refers to the fear of imminent danger or serious harm, especially when someone is forced to do something against their will. Metus is broader than the concept of duress in Anglo-American law, as it includes fear of any serious harm that could affect a reasonable person.

For example, if someone is threatened with physical harm or death unless they sign a contract, that would be considered metus. In Roman law, metus had the same effect as fraud when it came to avoiding a contract. It could be used as a defense (exceptio metus), or the victim could seek restitution (restitutio in integrum) or file a lawsuit (actio metus) against the perpetrator.

Metus can also refer to a threat that diminishes the value of someone else's property. In both senses, the victim was allowed to seek fourfold damages against the perpetrator. Metus was a serious offense in Roman law, and those who used it to harm others were punished severely.