What term describes the illegal use of threats or violence to coerce someone?

The term describing the illegal use of threats or violence to coerce someone is duress. Duress specifically refers to situations where an individual is compelled to act against their will due to threats of physical harm, making it a legal term often associated with the inability to consent freely.

When a person is under duress, their free will is effectively overridden, because they are pressured to make decisions they would not otherwise make if not for the fear induced by threats or violence. This makes the concept of duress essential in legal contexts, as it can invalidate contracts or agreements made under such coercive circumstances.

While terms like intimidation and coercion may involve threats, they do not necessarily encompass the physical element of violence associated with duress. Similarly, extortion is a form of coercion that specifically involves obtaining something, usually money, through threats, but it is not exclusively about forcing someone to act or forbear from acting against their will.