Meaning of twilight

(adj) lighted by or as if by twilight; "The dusky night rides down the sky/And ushers in the morn"-Henry Fielding; "the twilight glow of the sky"; "a boat on a twilit river"

(noun) the time of day immediately following sunset; "he loved the twilight"; "they finished before the fall of night"

the diffused light from the sky when the sun is below the horizon but its rays are refracted by the atmosphere of the earth

a condition of decline following successes; "in the twilight of the empire"