usurp
yoo-SURPverbMeaning to take a position or power without the right to it
Memory hook you SLURP my soup, you SIT on my throne?. While the king naps, the cat climbs onto his throne, puts on his crown and slurps his soup; it has no right to rule, but it usurps the throne.
The scheming duke tried to usurp the throne while the young queen was away.
In context The assistant coach began to usurp the head coach’s role, calling plays and giving speeches until no one knew who was really in charge.
Similar seize, take over, grab, arrogate
Opposite abdicate, surrender
From Latin usurpare, “to take into use, to seize”: usus (use) + rapere (to seize).