usurp

v. seize, take over, appropriate

"Usurp" redirects here. You might be also looking for Wikipedia:Changing username/Usurpations. This article is about a person asserting official authority. For the computer game, see Usurper (game). Usurper (lat. usurpare = to seize for use, to use) is a derogatory term used to describe either an illegitimate or controversial claimant to the throne in a monarchy, or a person who succeeds in establishing himself as a monarch without inheriting the throne, or any other person asserting official authority without having been delegated that authority. It may also be be applied to an official acting ultra vires, outside his authority or jurisdiction.
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Verb
1. seize and take control without authority and possibly with force; take as one's right or possession; "He assumed to himself the right to fill all positions in the town"; "he usurped my rights"; "She seized control of the throne after her husband died"
(synonym) assume, seize, take over, arrogate
(hypernym) take
(hyponym) annex
(derivation) usurpation
2. take the place of; "gloom had usurped mirth at the party after the news of the terorist act broke"
(hypernym) supplant, replace, supersede, supervene upon

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

(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.
  

Synonyms and related words:
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