The Collaborative International Dictionary of English v.0.48:

Abundant \A*bun"dant\, a. [OE. (h)abundant, aboundant, F.
   abondant, fr. L. abudans, p. pr. of abundare. See Abound.]
   Fully sufficient; plentiful; in copious supply; -- followed
   by in, rarely by with. "Abundant in goodness and truth."
   --Exod. xxxiv. 6.
   [1913 Webster]

   Abundant number (Math.), a number, the sum of whose aliquot
      parts exceeds the number itself. Thus, 1, 2, 3, 4, 6, the
      aliquot parts of 12, make the number 16. This is opposed
      to a deficient number, as 14, whose aliquot parts are 1,
      2, 7, the sum of which is 10; and to a perfect number,
      which is equal to the sum of its aliquot parts, as 6,
      whose aliquot parts are 1, 2., 3.
      [1913 Webster]

   Syn: Ample; plentiful; copious; plenteous; exuberant;
        overflowing; rich; teeming; profuse; bountiful; liberal.
        See Ample.
        [1913 Webster]

WordNet (r) 3.0 (2006):

abundant
    adj 1: present in great quantity; "an abundant supply of water"
           [ant: scarce]