A collapsed lung, also known as a pneumothorax, occurs when air escapes out of a lung and becomes trapped inside the space between the chest and lung cavities. This can be caused by air blisters in the lungs that break open, sudden air pressure changes, or trauma to the chest or ribcage.
The IRS interpreted this provision as applying only to full-time students. In a 1993 technical advice memorandum, the IRS provided a safe-harbor definition of a full-time undergraduate student as one who is taking 12 credit hours and working no more than 20 hours per week.
student (plural students) A person who studies or learns about a particular academic subject. A student of philosophy. (figuratively) A person seriously devoted to some subject, whether academic or not. He is a student of life. A person enrolled at a university. The students were out raising funds for rag week.