Source : Webster's Revised Unabridged Dictionary (1913)

Jest \Jest\, n. [OE. jeste, geste, deed, action, story, tale,
   OF. geste, LL. gesta, orig., exploits, neut. pl. from L.
   gestus, p. p. of gerere to bear, carry, accomplish, perform;
   perh. orig., to make to come, bring, and perh. akin to E.
   come. Cf. {Gest} a deed, {Register}, n.]
   1. A deed; an action; a gest. [Obs.]

            The jests or actions of princes.      --Sir T.
                                                  Elyot.

   2. A mask; a pageant; an interlude. [Obs.] --Nares.

            He promised us, in honor of our guest, To grace our
            banquet with some pompous jest.       --Kyd.

   3. Something done or said in order to amuse; a joke; a
      witticism; a jocose or sportive remark or phrase. See
      Synonyms under {Jest}, v. i.

            I must be sad . . . smile at no man's jests. --Shak.

            The Right Honorable gentleman is indebted to his
            memory for his jests, and to his imagination for his
            facts.                                --Sheridan.

   4. The object of laughter or sport; a laughingstock.

            Then let me be your jest; I deserve it. --Shak.

   {In jest}, for mere sport or diversion; not in truth and
      reality; not in earnest.

            And given in earnest what I begged in jest. --Shak.

   {Jest book}, a book containing a collection of jests, jokes,
      and amusing anecdotes; a Joe Miller.

Jest \Jest\, v. i. [imp. & p. p. {Jested}; p. pr. & vb. n.
   {Jesting}.]
   1. To take part in a merrymaking; -- especially, to act in a
      mask or interlude. [Obs.] --Shak.

   2. To make merriment by words or actions; to joke; to make
      light of anything.

            He jests at scars that never felt a wound. --Shak.

   Syn: To joke; sport; rally.

   Usage: To {Jest}, {Joke}. One jests in order to make others
          laugh; one jokes to please himself. A jest is usually
          at the expense of another, and is often ill-natured; a
          joke is a sportive sally designed to promote good
          humor without wounding the feelings of its object.
          ``Jests are, therefore, seldom harmless; jokes
          frequently allowable. The most serious subject may be
          degraded by being turned into a jest.'' --Crabb.

Source : WordNet®

jest
     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: {joke}, {gag}, {laugh},
           {jape}]
     2: activity characterized by good humor [syn: {joke}, {jocularity}]
     v 1: tell a joke; speak humorously; "He often jokes even when he
          appears serious" [syn: {joke}]
     2: act in a funny or teasing way [syn: {joke}]