/
jʊˈzəːp, 
jʊˈsəːp/
v.
  - take (a position of power) illegally or by force. ▸supplant (someone in power). 
- 
(usurp on/upon)
 archaic infringe on.
Derivative
- usurpation
 /ˌjuːzəˈpeɪʃ(ə)n, ˌjuːs-/
 n.
- usurper n.
Etymology
ME: from OFr. usurper, from L. usurpare ‘seize for use’.