comfortably
He seated himself comfortably at the foot of the bed.
The car seats six comfortably.

at
Ramirez was seated at a table near the window.

in
The old woman was seated in a chair.

on
She seated herself on the sofa.

be seated
Please be seated.

be seated cross-legged
remain seated, stay seated
Please remain seated until your name is called.

Seat is used with these nouns as the subject:
auditorium, dining room

Seat is used with these nouns as the object:
guest, spectator

available, empty, spare, vacant
There were no empty seats left in the hall.
Do you have a spare seat in your car?

comfortable, comfy
plush
cushioned, leather
plush leather seats

bicycle, car
back, front, middle, rear
I always feel sick if I sit in the back seat of the car.

driver's, driving, passenger
bucket
I slid into the leather bucket seat and fastened my seat belt.

booster, car, child, safety
airline, theatre/theater
aisle, window
I always ask for an aisle seat when I fly.

front-row, good, ringside
I got to the concert early to get a good seat.
We had ringside seats for the boxing match.

bleacher, bleachers
Seating will consist of 2 140 bleacher seats and 1 610 chairs.

bench
love (= a comfortable seat for two people to sit on)
ejection, ejector
lavatory, loo, toilet
usual
I took my usual seat at the front of the classroom.

find, get, grab, have, take
Please take a seat.
Is this seat taken?

occupy, sit on
The best seats were occupied by the friends and families of the performers.
It is very uncomfortable to sit on these seats.

get (up) out of, leave, rise from
give up, offer, vacate
He gave up his seat on the bus to a pregnant woman.

resume, return to
The audience resumed their seats for the second half of the play.

fill
Not all theatres/theaters can fill their seats so easily.

book, reserve
Is it possible to reserve seats for the play?

save
Can you save me a seat if you get there first?

lean back in, recline in, settle back in
lean forward in
settle into
We had hardly settled into our seats when the first goal was scored.

slide into
She slid into the driver's seat.

shift in
put back, recline

cover
cushion
reservation
Seat reservations are free.
an electronic seat-reservation system

in a/the seat
The man in the passenger seat seemed to be asleep.

on a/the seat
I found my gloves lying on the back seat.

out of a/the seat
He leaped out of his seat when he saw the rat.

seat for
I managed to get some seats for the ballet.

the best seat in the house
We had the best seats in the house for the concert.

lean back in your seat, settle back in your seat
We settled back into our seats and waited for the show to begin.

on the edge of your seat
With two minutes to go before the end, I was on the edge of my seat.

congressional, House, Senate
Republicans won 52.7% of the House seats.

Commons, parliamentary
council
board
the search for finance chiefs to fill board seats

marginal
open
The Democrats captured 18 of the 30 open seats.

safe
Democratic, Labour, Republican, Tory, etc.

gain, pick up, secure, take, win
Republicans gained five seats in the Senate.
The Liberals took seven seats from Labour.
The Labour candidate took the seat with a majority of 163.

lose
He lost his seat in the last election.

hold, keep, retain
The party held the seat with a 10 000 majority.

regain, win back
contest, fight, run for
He has been selected to fight the seat at the next election.
She is running for a seat in the New York State Assembly.

defend
take (= begin your duties in Parliament)
She took her seat in Parliament as Britain's youngest MP.

hold, occupy
Republicans currently hold 51 seats in the Senate.

resign, vacate

seat in
a seat in Congress

seat on
a seat on the board