sundowning

sundown +‎ -ing

sundowning (uncountable)

1. (medicine, psychology, psychiatry) A state of agitation, confusion, or delirium, especially in patients suffering from Alzheimer's disease, which begins daily at nightfall and which is alleviated by daylight.
   • 1986, Norma Sullivan and Barry Fogel, "Could This Be Delirium?," The American Journal of Nursing, vol. 86, no. 12, p. 1363,

     Impaired judgment and sundowning (increased confusion when orienting cues diminish at night) often makes it necessary to restrict and protect the delirious patient.

• nocturnal delirium
• sundowner syndrome

• sundowner

sundowning

1. present participle of sundown

• seasonal affective disorder