The Collaborative International Dictionary of English v.0.48:

Alight \A*light"\, v. i. [imp. & p. p. Alightedsometimes
   Alit; p. pr. & vb. n. Alighting.] [OE. alihten, fr. AS.
   [=a]l[imac]htan; pref. [=a]- (cf. Goth. us-, G. er-, orig.
   meaning out) + l[imac]htan, to alight, orig. to render light,
   to remove a burden from, fr. l[imac]ht, leoht, light. See
   Light, v. i.]
   1. To spring down, get down, or descend, as from on horseback
      or from a carriage; to dismount.
      [1913 Webster]

   2. To descend and settle, lodge, rest, or stop; as, a flying
      bird alights on a tree; snow alights on a roof.
      [1913 Webster]

   3. To come or chance (upon). [R.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Alight \A*light"\, a. [Pref. a- + light.]
   Lighted; lighted up; in a flame. "The lamps were alight."
   --Dickens.
   [1913 Webster]

WordNet (r) 3.0 (2006):

alight
    adj 1: lighted up by or as by fire or flame; "forests set ablaze
           (or afire) by lightning"; "even the car's tires were
           aflame"; "a night aflare with fireworks"; "candles alight
           on the tables"; "houses on fire" [syn: ablaze(p),
           afire(p), aflame(p), aflare(p), alight(p), on
           fire(p)]
    v 1: to come to rest, settle; "Misfortune lighted upon him"
         [syn: alight, light, perch]
    2: come down; "the birds alighted" [syn: alight, climb down]