illegality, n. 1. An act that is not authorized by law. 2. The state of not being legally authorized. “A contract made ultra vires is void; but not [strictly speaking] on the ground of illegality. Lord Cairns … takes exception to the use of the term ‘illegality,’ pointing out that it is not the object […]
sponsion (spon-sh[schwa]n), n. [fr. Latin spondere “to engage”] 1. The formal pledge by which a person becomes a surety. 2. Int’l law. An ultra vires promise of an official agent (such as a general in wartime), requiring later ratification by the principal. 3. Roman law. A form of guarantee accessory to an oral contract. •
越权 英语：ultra vires 法语：excès de pouvoir 德语：über die Befugnisse hinausgehend 意大利语：al di là dei poteri, arbitrariamente 西班牙语：acto de extralimitación de funciones en una sociedad