The Collaborative International Dictionary of English v.0.48:

Emulous \Em"u*lous\, a. [L. aemulus. See Emulate.]
   1. Ambitiously desirous to equal or even to excel another;
      eager to emulate or vie with another; desirous of like
      excellence with another; -- with of; as, emulous of
      another's example or virtues.
      [1913 Webster]

   2. Vying with; rivaling; hence, contentious, envious.
      "Emulous Carthage." --B. Jonson.
      [1913 Webster]

            Emulous missions 'mongst the gods.    --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

emulous
    adj 1: characterized by or arising from emulation or imitation
    2: eager to surpass others [syn: emulous, rivalrous]