Webster’s Revised Unabridged Dictionary · 1913
Sunset
Sun′set′, Sun′set′ting, n. 1. The descent of the sun below the horizon; also, the time when the sun sets; evening. Also used figuratively.
'T is the sunset of life gives me mystical lore. Campbell.
2. Hence, the region where the sun sets; the west.
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.