noun
1
BAD : During the flight she sat on the chair behind me.
GOOD : During the flight she sat in the seat behind me.
◆◆◆
seat = a place to sit, as found in a cinema, train, bus etc: 'To be on the safe side, you'd better reserve a seat.'
chair = a movable seat for one person: 'Before the children go home, they have to put all the chairs on top of the desks.'
2
See ARMCHAIR (↑ armchair )