1. [n]  the diffused light from the sky when the sun is below the horizon but its rays are refracted by the atmosphere of the earth
2. [n]  a state of diffused or dim illumination
3. [n]  a condition of decline following successes; "in the twilight of the empire"
4. [n]  the time of day immediately following sunset; "he loved the twilight"; "they finished before the fall of night"

TWILIGHT is a 8 letter word that starts with T.

1. \Twi"light`\, n. [OE. twilight, AS. twi- (see {Twice})
   + le['o]ht light; hence the sense of doubtful or half light;
   cf. LG. twelecht, G. zwielicht. See {Light}.]
   1. The light perceived before the rising, and after the
      setting, of the sun, or when the sun is less than 18[deg]
      below the horizon, occasioned by the illumination of the
      earth's atmosphere by the direct rays of the sun and their
      reflection on the earth.
   
   2. faint light; a dubious or uncertain medium through which
      anything is viewed.
   
            As when the sun . . . from behind the moon, In dim
            eclipse, disastrous twilight sheds.   --Milton.
   
            The twilight of probability.          --Locke.
   
   

2. \Twi"light`\, a.
   1. Seen or done by twilight. --Milton.
   
   2. Imperfectly illuminated; shaded; obscure.
   
            O'er the twilight groves and dusky caves. --Pope.