Source : Webster's Revised Unabridged Dictionary (1913)

Zeal \Zeal\ (z[=e]l), n. [F. z[`e]le; cf. Pg. & It. zelo, Sp.
   zelo, celo; from L. zelus, Gr. ?, probably akin to ? to boil.
   Cf. {Yeast}, {Jealous}.]
   1. Passionate ardor in the pursuit of anything; eagerness in
      favor of a person or cause; ardent and active interest;
      engagedness; enthusiasm; fervor. ``Ambition varnished o'er
      with zeal.'' --Milton. ``Zeal, the blind conductor of the
      will.'' --Dryden. ``Zeal's never-dying fire.'' --Keble.

            I bear them record that they have a zeal of God, but
            not according to knowledge.           --Rom. x. 2.

            A zeal for liberty is sometimes an eagerness to
            subvert with little care what shall be established.
                                                  --Johnson.

   2. A zealot. [Obs.] --B. Jonson.

Zeal \Zeal\, v. i.
   To be zealous. [Obs. & R.] --Bacon.

Source : WordNet®

zeal
     n 1: a feeling of strong eagerness (usually in favor of a person
          or cause); "they were imbued with a revolutionary
          ardor"; "he felt a kind of religious zeal" [syn: {ardor},
           {ardour}, {elan}]
     2: excessive fervor to do something or accomplish some end; "he
        had an absolute zeal for litigation"