dusk;  twilight;  twilight years;  melancholia;  melancholic nostalgia
 dark;  gloomy;  depressed;  dispirited;  dark (in colour);  dull;  ill-boding
 to fade into dusk;  to fade into twilight;  to decline;  to wane;  to look melancholic (of a person)
 fast asleep;  dead to the world
 stupefaction;  stupor;  unconsciousness;  confusion
 to get dark;  to grow dark;  to end (of a day, year, season, etc.);  to come to an end;  to be sunk in (e.g. despair);  to be lost in (e.g. thought)
 befuddled (bewildered, confused) state;  stupor
 fast asleep;  dead to the world
 lesser cuckoo (Cuculus poliocephalus)