unseat

Short definition from Wiktionary

Verb

1. 1
   To dislodge or remove (someone) from a seat, especially on horseback.
2. 2
   To remove (someone) from an office or position, especially a political one; to dethrone.
3. 3
   To cause (something) to be removed or replaced in its role; to displace, to overturn.
4. 4
   To upset the composure of (someone); to astound, to shock, to unsettle.
5. 5
   To come off or out of a seat.