Meaning of “seat” - Learner’s Dictionary

seat

noun [ C ] uk us /siːt/
SIT

A2 something that you sit on:

Please, have/take a seat (= sit down).
I've booked three seats for the cinema tonight.
the back/front seat of a car
PART

the flat part of a chair, bicycle, etc that you sit on

POLITICS

a position in a parliament or other group that makes official decisions:

a seat in parliament

(Definition of “seat noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)