Source : Webster's Revised Unabridged Dictionary (1913)

Joke \Joke\, n. [L. jocus. Cf {Jeopardy}, {Jocular}, {Juggler}.]
   1. Something said for the sake of exciting a laugh; something
      witty or sportive (commonly indicating more of hilarity or
      humor than jest); a jest; a witticism; as, to crack
      good-natured jokes.

            And gentle dullness ever loves a joke. --Pope.

            Or witty joke our airy senses moves To pleasant
            laughter.                             --Gay.

   2. Something not said seriously, or not actually meant;
      something done in sport.

            Inclose whole downs in walls, 't is all a joke.
                                                  --Pope.

   {In joke}, in jest; sportively; not meant seriously.

   {Practical joke}. See under {Practical}.

Joke \Joke\, v. t. [imp. & p. p. {Joked}; p. pr. & vb. n.
   {Joking}.]
   To make merry with; to make jokes upon; to rally; to banter;
   as, to joke a comrade.

Joke \Joke\, v. i. [L. jocari.]
   To do something for sport, or as a joke; to be merry in words
   or actions; to jest.

         He laughed, shouted, joked, and swore.   --Macaulay.

   Syn: To jest; sport; rally; banter. See {Jest}.

Source : WordNet®

joke
     n 1: a humorous anecdote or remark intended to provoke laughter;
          "he told a very funny joke"; "he knows a million gags";
          "thanks for the laugh"; "he laughed unpleasantly at
          hisown jest"; "even a schoolboy's jape is supposed to
          have some ascertainable point" [syn: {gag}, {laugh}, {jest},
           {jape}]
     2: activity characterized by good humor [syn: {jest}, {jocularity}]
     3: a ludicrous or grotesque act done for fun and amusement
        [syn: {antic}, {prank}, {trick}, {caper}, {put-on}]
     4: a triviality not to be taken seriously; "I regarded his
        campaign for mayor as a joke"

joke
     v 1: tell a joke; speak humorously; "He often jokes even when he
          appears serious" [syn: {jest}]
     2: act in a funny or teasing way [syn: {jest}]