a movable flat object that closes the entrance to a room, cupboard etc

entrance to room, building

an opening in a hedge, fence, wall etc able to be closed by a barrier; a barrier used to control the passage of water, e.g. into or out of a dam

movable barrier at entrance

gaol; prison

place for incarceration

(especially US) a prison

prison, jail

a building in which a person who commits a crime is kept locked up

residence for incarcerating criminals

a wall of upright posts, built as a defence

enclosure; jail

a revolving gate that allows one person through at a time

movable barrier at entrance