What term describes an authority exceeding the limits of their given powers?

The term that describes an authority exceeding the limits of their given powers is "ultra vires." This Latin phrase translates to "beyond the powers" in English, and it is commonly used in legal contexts to refer to an action taken by a governing body, organization, or individual that falls outside the scope of their legal authority. When an action is deemed ultra vires, it is typically considered void and unenforceable because the individual or organization did not have the legal power to take that action.

The understanding of this term is particularly important in fields such as corporate law, where decisions made by directors or officers are scrutinized to ensure they are within the bounds of their authorized powers. For instance, if a company’s board attempts to enter into a contract that is beyond the scope of their authority as defined by the company's bylaws, that action can be declared ultra vires.

The other terms relate to different legal concepts: "intra vires" refers to actions conducted within the limits of legal authority; "subpoena" is a document that orders an individual to testify or produce evidence; and a "grand jury" is a group that examines evidence to decide whether to indict someone on criminal charges. Thus, these options do not align