Source : Webster's Revised Unabridged Dictionary (1913)

Discoverer \Dis*cov"er*er\, n.
   1. One who discovers; one who first comes to the knowledge of
      something; one who discovers an unknown country, or a new
      principle, truth, or fact.

            The discoverers and searchers of the land. --Sir W.
                                                  Raleigh.

   2. A scout; an explorer. --Shak.

Source : WordNet®

discoverer
     n 1: someone who is the first to think of or make something [syn:
           {inventor}, {artificer}]
     2: someone who is the first to observe something [syn: {finder},
         {spotter}]