Refers to the dim light after sunset but before full darkness; slightly literary or formal in tone.
The first star began to shine in the twilight sky.
It is said that traffic accidents increase during the twilight hours.
薄暮 is a formal, often technical term (used in weather reports or military contexts) for the dim light of dusk, while 夕闇 carries a more literary, atmospheric feel.
薄暮 is a formal, technical term (used e.g. in weather or aviation reports) for the twilight period, while 夕暮れ is the everyday literary word for the same time.
crepuscular
Compound of 薄 (thin, faint) and 暮 (dusk, end of day), literally 'faint dusk'.