Webster’s Revised Unabridged Dictionary · 1913
Usurper
U·surp′er (·ẽr), n. One who usurps; especially, one who seizes illegally on sovereign power; as, the usurper of a throne, of power, or of the rights of a patron.
A crown will not want pretenders to claim it, not usurpers, if their power serves them, to possess it. South.