sundowning

noun

sun·​down·​ing ˈsən-ˌdau̇-niŋ 

: a state of increased agitation, confusion, disorientation, and anxiety that typically occurs in the late afternoon or evening in some individuals affected with dementia

Shorter days during winter months can increase the risk of "sundowning." Monitor closely for agitation or restlessness as day transitions into night.

—Marisa Korytko

Sundowning affects up to two-thirds of patients with dementia, and it may be a sign that the disease is progressing.

—Patti Thummel

Examples of sundowning in a Sentence

Recent Examples on the Web

Regardless of the timeline for the ISS, SpaceX's planned sundowning of Falcon 9 also hinges on Starship's success. — Josh Dinner, Space.com, 24 Aug. 2026

Word History

Etymology

sundown + -ing entry 1, after earlier sundowner syndrome in same sense

First Known Use

1978, in the meaning defined above

Rhymes for sundowning

• clowning
• crowning
• downing
• drowning
• frowning

Medical Definition

sundowning

noun

sun·​down·​ing ˈsən-ˌdau̇n-iŋ 

: a state of increased agitation, confusion, disorientation, and anxiety that typically occurs in the late afternoon or evening in some individuals affected with dementia

Sundowning is a major problem in the middle and late stages of disorders, such as Alzheimer's disease, that cause dementia.

—Patricia N. Prinz et al., The New England Journal of Medicine