(stuffier, stuffiest)
1.
Stuffy people or institutions are formal and old-fashioned.
Why were grown-ups always so ~ and slow to recognize good ideas?
...a firm of lawyers in Lincoln’s Inn, immensely ~ and respectable.
ADJ disapproval
2.
If it is ~ in a place, it is unpleasantly warm and there is not enough fresh air.
It was hot and ~ in the classroom.
ADJ