yüˈs]ərpər, -]ə̄pə(r, -]əipə(r sometimes -ˈz\ noun
( -s )
Etymology: Middle English, from usurpen to usurp + -er
: one that usurps: as
a. : one that seizes illegally on sovereign power
a usurper who should make himself master of the relics would be acknowledged king without dispute — J.G.Frazer
b. : one that infringes or encroaches upon the rights or property of another
c. : one that without proper authority assumes public office and performs official acts