1. (v. t.) To seize, and hold by force, or without right; as, to usurp a throne; to usurp power\; to usurp the right of a patron is to oust or dispossess him.

2. (v. i.) To commit forcible seizure of place, power, functions, or the like, without right; to commit unjust encroachments; to be, or act as, a usurper.

accroach adopt advance upon appropriate arrogate assume assume command break bounds colonize commandeer conquer cut out displace encroach enslave go too far hog indent infringe intrude invade irrupt jump a claim know no bounds make an inroad make free with make use of monopolize mount the throne occupy overrun overstep overstep the bounds play God preempt preoccupy prepossess pretend to requisition seize seize power seize the throne sit on squat on subjugate take all of take charge take command take it all take over take possession of take the helm take the lead take up transgress trespass