Source : Webster's Revised Unabridged Dictionary (1913)

Nemesis \Nem"e*sis\, n. [L., fr. gr. ?, orig., distribution, fr.
   ? to distribute. See {Nomad}.] (Class. Myth.)
   The goddess of retribution or vengeance; hence, retributive
   justice personified; divine vengeance.

         This is that ancient doctrine of nemesis who keeps
         watch in the universe, and lets no offense go
         unchastised.                             --Emerson.

Source : WordNet®

Nemesis
     n 1: (Greek mythology) the goddess of divine retribution and
          vengeance
     2: something causes misery or death; "the bane of my life"
        [syn: {bane}, {curse}, {scourge}]