i Register
In some senses, sundown is marked as US. Watch for register when choosing this word.
noun
Sunset.
We’ll meet by the pier at sundown.
Yet oft when sundown skirts the moor An inner trouble I behold, A spectral doubt which makes me cold, That I shall be thy mate no more, […]
A hat with a wide brim to shade the eyes from sunlight.
verb
to experience an episode or an onset of some detrimental mental condition like agitation, anxiety, hallucination or dementia, daily at nightfall.
"She also “sundowned”, and someone had to keep an eye on her 24-7."