usurper (u-surp-er)
Definition
noun. A person who takes a position of power or importance illegally or by force.
Example Sentence
The usurper seized the throne, causing unrest throughout the kingdom.
More Example Sentences
In many tales, the usurper is eventually overthrown by the rightful heir.
Synonyms
intruder; impostor; pretender
Antonyms
legitimate ruler; rightful owner; lawful leader