The descent of the sun below the horizon; also, the time when the sun sets; evening. Also used figuratively. [1913 Webster]
"'T is the sunset of life gives me mystical lore."
[1913 Webster]
Hence, the region where the sun sets; the west. [1913 Webster]
Sunset shell(Zoöl.), a West Indian marine bivalve (Tellina radiata) having a smooth shell marked with radiating bands of varied colors resembling those seen at sunset or before sunrise; -- called also rising sun.