definition of
usurp

[1] #1 usurp v. [assume, seize, take over, arrogate] 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". wn

[2] #2 usurp v. take the place of; "gloom had usurped mirth at the party after the news of the terrorist act broke". wn