Pathology. A disorder characterized by morbid drowsiness or prolonged and unnatural sleep.

In general and figurative senses.

A deep, lethargic, or unnatural sleep or state of sleep. In later use Pathology.

Medicine. Somnolence or stupor produced by disease. Obsolete.

a condition characterized by abnormally long or frequent periods, or abnormal depth, of sleep.

A sleep disorder, often of genetic origin, characterized by frequent brief episodes of sleep during the day and disturbed nocturnal sleep, often…

= narcolepsy, n.