ADJ

empty, spare, vacant
There were no empty seats left in the hall. Do you have a spare seat in your car?
comfortable, comfy
cushioned
bicycle, car
back, front, rear
I always feel sick if I sit in the back seat of the car
driver's, driving, passenger
baby, child, safety
pillion
I had a terrifying journey on the pillion seat of a Honda 750
aisle, window
I always ask for an aisle seat when I fly
lavatory, toilet
good, ringside
I got to the theatre early to get a good seat. We had ringside seats for the boxing match

VERB + SEAT

get, have, take
Please take a seat. Is this seat taken?
book, reserve
Is it possible to book seats for the play?
save
Can you save me a seat if you get there first?
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
resume
The audience resumed their seats for the second half of the play
give up, vacate
He gave up his seat on the bus to a pregnant woman
lean back in, recline in, settle back in
settle into
We had hardly settled into our seats when the first goal was scored
get (up) out of
put back, recline

SEAT + NOUN

cover
reservation

PREP

in a/the ~
The man in the passenger seat seemed to be asleep
on a/the ~
I found my gloves lying on the back seat
out of a/the ~
He leapt out of his seat when he saw the rat
~ for
I managed to get some seats for the ballet

ADJ

congressional, parliamentary, Senate
marginal
safe
Labour, Tory, etc.

VERB + SEAT

gain, win
lose
He lost his seat in the last election
keep, retain
regain
contest
resign

PREP

~ in
a seat in Parliament
~ on
a seat on the local council