narcolepsy

/ˌnɑrkəˈlɛpsi/

/ˈnɑkəlɛpsi/

If it seems like your dad is always dozing on the couch, he may be lazy or he may suffer from narcolepsy — a disorder that makes people fall asleep, sometimes suddenly.

Someone who's diagnosed with narcolepsy may abruptly fall asleep at any moment, although there are milder cases of narcolepsy with symptoms including excessive fatigue during the day and the need for frequent naps. A person with narcolepsy is called a narcoleptic. The French term narcolepsie was coined in 1880 by a French doctor who took the Greek word narke, "numbness," and combined it with lepsis, "attack or seizure."

Definitions of narcolepsy

1. noun

   a sleep disorder characterized by sudden and uncontrollable episodes of deep sleep
   “he believes that narcolepsy is attributable to an inability to suppress REM sleep during waking”

   type of:

   hypersomnia

   an inability to stay awake