If you feel claustrophobic, a small closed space starts to scare you: a lift, a packed train, a room with no window, a cave. Your chest feels tight. You want out. The word also covers a looser feeling about life, not only rooms. A job, a marriage, or a little town can feel claustrophobic when it limits what you can do and you cannot step away. People use the word in three everyday ways: for the person who has that fear, for the place that causes it, and for the trapped feeling itself. Though actually, everyday talk stretches it. Someone who merely dislikes a crowd may say “I feel claustrophobic” without the strong, lasting fear a doctor would name claustrophobia. It is ordinary English; about rooms it sounds serious, about life it sounds a little dramatic.