cleithr-, cleithro- +

(Greek: bar for closing a door; to shut, to close)

cleistophobia, cleithrophobia (s) (nouns); cleistophobias, cleithrophobias (pl)
An intensive fear of being in closed places or of being locked in some small space: There are people who are afflicted with cleistophobia and cannot tolerate being in a car, in a train, in a street car, or in a room in which they cannot open a window or the door.
cleithrophobia, cleisiophobia, clithrophobia (s) (noun); cleithrophobias, cleisiophobias, clithrophobias (pl)
A morbid fear of being enclosed or of closed areas, such as a form of claustrophobia: The psychiatrist has several patients who are suffering from clithrophobia because they are frightened of being locked in a room.