1. Morbid fear of choking: Greg's father had an angina pectoris or a heart condition marked by a sudden uncontrollable attack of chest pain as a result of reduced oxygen to the heart, and Greg was terrified that he himself could suffer from pnigophobia.
2. An abnormal fear of suffocating: When Susan, afflicted by pnigophobia, had a bad cold and couldn't breathe through her nose, she used nose drops to make sure she wouldn't be short of air and would be able to breathe easily during the night.
3. Etymology: from Greek pnigos, "choking" + phobos, "fear, dread".