Which term refers to the annulment or cancellation of a legal instrument by the party who made it?

The term that refers to the annulment or cancellation of a legal instrument by the party who made it is "revocation." Revocation involves an intentional action taken by the party who holds the authority to nullify the legal instrument, thereby rendering it void and without effect. This concept is crucial in various legal contexts, including contracts, wills, and powers of attorney, where one party seeks to withdraw or cancel their previous consent or agreement.

The term "restitution" refers to the act of restoring or returning something to its original state or compensating for loss, but it does not specifically refer to the cancellation of a legal instrument. "Rescission" is closely related and often used interchangeably in some contexts; however, it generally implies that a legal contract is terminated and the parties are restored to their pre-contractual positions, rather than merely annulling the instrument by the party who created it. "Termination" is a broader term that denotes the ending of a contractual agreement or legal relationship but does not specifically convey the act of one party cancelling an instrument they originally established. Therefore, revocation precisely describes the action of cancelling a legal instrument by the party who created it.