Source : Webster's Revised Unabridged Dictionary (1913)

Plenty \Plen"ty\, n.; pl. {Plenties}, in --Shak. [OE. plentee,
   plente, OF. plent['e], fr. L. plenitas, fr. plenus full. See
   {Full}, a., and cf. {Complete}.]
   Full or adequate supply; enough and to spare; sufficiency;
   specifically, abundant productiveness of the earth; ample
   supply for human wants; abundance; copiousness. ``Plenty of
   corn and wine.'' --Gen. xxvii. 28. ``Promises Britain peace
   and plenty.'' --Shak.

         Houses of office stuffed with plentee.   --Chaucer.

         The teeming clouds Descend in gladsome plenty o'er the
         world.                                   --Thomson.

   Syn: Abundance; exuberance. See {Abundance}.

Plenty \Plen"ty\, a.
   Plentiful; abundant. [Obs. or Colloq.]

         If reasons were as plenty as blackberries. --Shak.
                                                  (Folio ed.)

         Those countries where shrubs are plenty. --Goldsmith.

Source : WordNet®

plenty
     n 1: a full supply; "there was plenty of food for everyone" [syn:
           {plentifulness}, {plenteousness}, {plenitude}, {plentitude}]
     2: (often followed by `of') a large number or amount or extent;
        "a batch of letters"; "a deal of trouble"; "a lot of
        money"; "he made a mint on the stock market"; "it must
        have cost plenty" [syn: {batch}, {deal}, {flock}, {good
        deal}, {great deal}, {hatful}, {heap}, {lot}, {mass}, {mess},
         {mickle}, {mint}, {muckle}, {peck}, {pile}, {pot}, {quite
        a little}, {raft}, {sight}, {slew}, {spate}, {stack}, {tidy
        sum}, {wad}, {whole lot}, {whole slew}]
     adv : as much as necessary; "Have I eaten enough?"; (`plenty' is
           nonstandard) "I've had plenty, thanks" [syn: {enough}]