Source : Webster's Revised Unabridged Dictionary (1913)

Jealousy \Jeal"ous*y\, n.; pl. {Jealousies}. [ F. jalousie. See
   {Jealous}, and cf. {Jalousie}.]
   The quality of being jealous; earnest concern or solicitude;
   painful apprehension of rivalship in cases nearly affecting
   one's happiness; painful suspicion of the faithfulness of
   husband, wife, or lover.

         I was jealous for jealousy.              --Zech. viii.
                                                  2.

         Jealousy is the . . . apprehension of superiority.
                                                  --Shenstone.

         Whoever had qualities to alarm our jealousy, had
         excellence to deserve our fondness.      --Rambler.

Source : WordNet®

jealousy
     n 1: a feeling of jealous envy (especially of a rival) [syn: {green-eyed
          monster}]
     2: zealous vigilance; "cherish their official political freedom
        with fierce jealousy"-Paul Blanshard