Final answer:
Duress by threat is a concept in contract law that makes a contract voidable. It occurs when one party is forced to enter into a contract against their will because of threats made by the other party.
Step-by-step explanation:
Duress by threat is a concept in contract law. It refers to a situation where one party is forced to enter into a contract against their will because of threats made by the other party. This can make the contract voidable, meaning that the party under duress has the option to either affirm the contract or rescind it. For example, if someone threatens to harm you unless you sign a contract, the contract may be voidable due to duress by threat.