n. The act of usurping; the act of seizing or occupying and enjoying the place, power, functions, or property of another without right; especially, the wrongful occupation of a throne: as, the usurpation of supreme power.n. In law: Intrusion into an office or assumption of a franchise, whether on account of vacancy or by ousting the incumbent, without any color of title.n. Such intrusion or assumption without lawful title.n. The absolute ouster and dispossession of the patron of a church by presenting a clerk to a vacant benefice, who is thereupon admitted and instituted; intrusion. Use; usage.