Source : Webster's Revised Unabridged Dictionary (1913)

Plethora \Pleth"o*ra\, n. [NL., fr. Gr. ?, fr. ? to be or become
   full. Cf. {Pleonasm}.]
   1. Overfullness; especially, excessive fullness of the blood
      vessels; repletion; that state of the blood vessels or of
      the system when the blood exceeds a healthy standard in
      quantity; hyper[ae]mia; -- opposed to an[ae]mia.

   2. State of being overfull; excess; superabundance.

            He labors under a plethora of wit and imagination.
                                                  --Jeffrey.

Source : WordNet®

plethora
     n : extreme excess; "an embarrassment of riches" [syn: {overplus},
          {superfluity}, {embarrassment}]