Definition of Usurpation

Torts. The unlawful assumption of the use of property which belongs to another; an interruption or the disturbing a man in his right and possession. Tomlins. In public law. The unlawful seizure or assumption of sovereign power; the assumption of government or supreme power by force or illegally, in derogation of the constitution and of the rights of the lawful ruler.
—Usurpation of advowson. An injury which consists in the absolute ouster or dispossession of the patron from the advowson or right of presentation, and which happens when a stranger who bas no right presents a clerk, and the latter is thereupon admitted and instituted. Brown.
—Usurpation of franchise or office. The unjustly intruding upon or exercising any office, franchise, or liberty belonging to another.