Source : Webster's Revised Unabridged Dictionary (1913)

Excursion \Ex*cur"sion\ [L. excursio: cf. F. excursion. See
   {Excurrent}.]
   1. A running or going out or forth; an expedition; a sally.

            Far on excursion toward the gates of hell. --Milton.

            They would make excursions and waste the country.
                                                  --Holland.

   2. A journey chiefly for recreation; a pleasure trip; a brief
      tour; as, an excursion into the country.

   3. A wandering from a subject; digression.

            I am not in a scribbling mood, and shall therefore
            make no excursions.                   --Cowper.

   4. (Mach.) Length of stroke, as of a piston; stroke. [An
      awkward use of the word.]

   Syn: Journey; tour; ramble; jaunt. See {Journey}.

Source : WordNet®

excursion
     n 1: a journey taken for pleasure; "many summer excursions to the
          shore"; "it was merely a pleasure trip"; "after cautious
          sashays into the field" [syn: {jaunt}, {outing}, {junket},
           {pleasure trip}, {expedition}, {sashay}]
     2: wandering from the main path of a journey [syn: {digression}]