IPA: /juːˈzɜːrpər/
KK: /juːˈzɜːrpər/
A person who takes control of something, especially a position of power, without the right to do so.
The usurper claimed the throne after overthrowing the rightful king.
Usurper → It is formed from "usurpare" (meaning to seize or take over) and the suffix "-er" (meaning a person who). An usurper is a person who seizes power or position unlawfully or by force.
Think of someone who 'seizes' ('usurpare') power unlawfully — that's why an usurper is someone who takes over a position.